P. 120 of Theorem List - Intuitionistic Logic Explorer

Theorem List for Intuitionistic Logic Explorer - 11901-12000   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	climcvg1n 11901*	A Cauchy sequence of complex numbers converges, existence version. The rate of convergence is fixed: all terms after the nth term must be within C / n of the nth term, where C is a constant multiplier. (Contributed by Jim Kingdon, 23-Aug-2021.)
|- ( ph -> F : NN --> CC )   &    |- ( ph -> C e. RR+ )   &    |- ( ph -> A. n e. NN A. k e. ( ZZ>= ` n ) ( abs ` ( ( F ` k ) - ( F ` n ) ) ) < ( C / n ) )   =>    |- ( ph -> F e. dom ~~> )
Theorem	climcaucn 11902*	A converging sequence of complex numbers is a Cauchy sequence. This is like climcau 11898 but adds the part that ( F ` k ) is complex. (Contributed by Jim Kingdon, 24-Aug-2021.)
|- Z = ( ZZ>= ` M )   =>    |- ( ( M e. ZZ /\ F e. dom ~~> ) -> A. x e. RR+ E. j e. Z A. k e. ( ZZ>= ` j ) ( ( F ` k ) e. CC /\ ( abs ` ( ( F ` k ) - ( F ` j ) ) ) < x ) )
Theorem	serf0 11903*	If an infinite series converges, its underlying sequence converges to zero. (Contributed by NM, 2-Sep-2005.) (Revised by Mario Carneiro, 16-Feb-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> F e. V )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) e. CC )   =>    |- ( ph -> F ~~> 0 )
4.9.2  Finite and infinite sums
Syntax	csu 11904	Extend class notation to include finite summations. (An underscore was added to the ASCII token in order to facilitate set.mm text searches, since "sum" is a commonly used word in comments.)
class sum_ k e. A B
Definition	df-sumdc 11905*	Define the sum of a series with an index set of integers A. The variable k is normally a free variable in B, i.e., B can be thought of as B ( k ). This definition is the result of a collection of discussions over the most general definition for a sum that does not need the index set to have a specified ordering. This definition is in two parts, one for finite sums and one for subsets of the upper integers. When summing over a subset of the upper integers, we extend the index set to the upper integers by adding zero outside the domain, and then sum the set in order, setting the result to the limit of the partial sums, if it exists. This means that conditionally convergent sums can be evaluated meaningfully. For finite sums, we are explicitly order-independent, by picking any bijection to a 1-based finite sequence and summing in the induced order. In both cases we have an if expression so that we only need B to be defined where k e. A. In the infinite case, we also require that the indexing set be a decidable subset of an upperset of integers (that is, membership of integers in it is decidable). These two methods of summation produce the same result on their common region of definition (i.e., finite sets of integers). Examples: sum_ k e. { 1 , 2 , 4 } k means 1 + 2 + 4 = 7, and sum_ k e. NN ( 1 / ( 2 ^ k ) ) = 1 means 1/2 + 1/4 + 1/8 + ... = 1 (geoihalfsum 12073). (Contributed by NM, 11-Dec-2005.) (Revised by Jim Kingdon, 21-May-2023.)
|- sum_ k e. A B = ( iota x ( E. m e. ZZ ( A C_ ( ZZ>= ` m ) /\ A. j e. ( ZZ>= ` m )DECID j e. A /\ seq m ( + , ( n e. ZZ |-> if ( n e. A , [_ n / k ]_ B , 0 ) ) ) ~~> x ) \/ E. m e. NN E. f ( f : ( 1 ... m ) -1-1-onto-> A /\ x = ( seq 1 ( + , ( n e. NN |-> if ( n <_ m , [_ ( f ` n ) / k ]_ B , 0 ) ) ) ` m ) ) ) )
Theorem	sumeq1 11906	Equality theorem for a sum. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jun-2019.)
|- ( A = B -> sum_ k e. A C = sum_ k e. B C )
Theorem	nfsum1 11907	Bound-variable hypothesis builder for sum. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jun-2019.)
|- F/_ k A   =>    |- F/_ k sum_ k e. A B
Theorem	nfsum 11908	Bound-variable hypothesis builder for sum: if x is (effectively) not free in A and B, it is not free in sum_ k e. A B. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jun-2019.)
|- F/_ x A   &    |- F/_ x B   =>    |- F/_ x sum_ k e. A B
Theorem	sumdc 11909*	Decidability of a subset of upper integers. (Contributed by Jim Kingdon, 1-Jan-2022.)
|- ( ph -> M e. ZZ )   &    |- ( ph -> A C_ ( ZZ>= ` M ) )   &    |- ( ph -> A. x e. ( ZZ>= ` M )DECID x e. A )   &    |- ( ph -> N e. ZZ )   =>    |- ( ph -> DECID N e. A )
Theorem	sumeq2 11910*	Equality theorem for sum. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jul-2013.)
|- ( A. k e. A B = C -> sum_ k e. A B = sum_ k e. A C )
Theorem	cbvsum 11911	Change bound variable in a sum. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jun-2019.)
|- ( j = k -> B = C )   &    |- F/_ k A   &    |- F/_ j A   &    |- F/_ k B   &    |- F/_ j C   =>    |- sum_ j e. A B = sum_ k e. A C
Theorem	cbvsumv 11912*	Change bound variable in a sum. (Contributed by NM, 11-Dec-2005.) (Revised by Mario Carneiro, 13-Jul-2013.)
|- ( j = k -> B = C )   =>    |- sum_ j e. A B = sum_ k e. A C
Theorem	cbvsumi 11913*	Change bound variable in a sum. (Contributed by NM, 11-Dec-2005.)
|- F/_ k B   &    |- F/_ j C   &    |- ( j = k -> B = C )   =>    |- sum_ j e. A B = sum_ k e. A C
Theorem	sumeq1i 11914*	Equality inference for sum. (Contributed by NM, 2-Jan-2006.)
|- A = B   =>    |- sum_ k e. A C = sum_ k e. B C
Theorem	sumeq2i 11915*	Equality inference for sum. (Contributed by NM, 3-Dec-2005.)
|- ( k e. A -> B = C )   =>    |- sum_ k e. A B = sum_ k e. A C
Theorem	sumeq12i 11916*	Equality inference for sum. (Contributed by FL, 10-Dec-2006.)
|- A = B   &    |- ( k e. A -> C = D )   =>    |- sum_ k e. A C = sum_ k e. B D
Theorem	sumeq1d 11917*	Equality deduction for sum. (Contributed by NM, 1-Nov-2005.)
|- ( ph -> A = B )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B C )
Theorem	sumeq2d 11918*	Equality deduction for sum. Note that unlike sumeq2dv 11919, k may occur in ph. (Contributed by NM, 1-Nov-2005.)
|- ( ph -> A. k e. A B = C )   =>    |- ( ph -> sum_ k e. A B = sum_ k e. A C )
Theorem	sumeq2dv 11919*	Equality deduction for sum. (Contributed by NM, 3-Jan-2006.) (Revised by Mario Carneiro, 31-Jan-2014.)
|- ( ( ph /\ k e. A ) -> B = C )   =>    |- ( ph -> sum_ k e. A B = sum_ k e. A C )
Theorem	sumeq2ad 11920*	Equality deduction for sum. (Contributed by Glauco Siliprandi, 5-Apr-2020.)
|- ( ph -> B = C )   =>    |- ( ph -> sum_ k e. A B = sum_ k e. A C )
Theorem	sumeq2sdv 11921*	Equality deduction for sum. (Contributed by NM, 3-Jan-2006.)
|- ( ph -> B = C )   =>    |- ( ph -> sum_ k e. A B = sum_ k e. A C )
Theorem	2sumeq2dv 11922*	Equality deduction for double sum. (Contributed by NM, 3-Jan-2006.) (Revised by Mario Carneiro, 31-Jan-2014.)
|- ( ( ph /\ j e. A /\ k e. B ) -> C = D )   =>    |- ( ph -> sum_ j e. A sum_ k e. B C = sum_ j e. A sum_ k e. B D )
Theorem	sumeq12dv 11923*	Equality deduction for sum. (Contributed by NM, 1-Dec-2005.)
|- ( ph -> A = B )   &    |- ( ( ph /\ k e. A ) -> C = D )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B D )
Theorem	sumeq12rdv 11924*	Equality deduction for sum. (Contributed by NM, 1-Dec-2005.)
|- ( ph -> A = B )   &    |- ( ( ph /\ k e. B ) -> C = D )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B D )
Theorem	sumfct 11925*	A lemma to facilitate conversions from the function form to the class-variable form of a sum. (Contributed by Mario Carneiro, 12-Aug-2013.) (Revised by Jim Kingdon, 18-Sep-2022.)
|- ( A. k e. A B e. CC -> sum_ j e. A ( ( k e. A |-> B ) ` j ) = sum_ k e. A B )
Theorem	fz1f1o 11926*	A lemma for working with finite sums. (Contributed by Mario Carneiro, 22-Apr-2014.)
|- ( A e. Fin -> ( A = (/) \/ ( (♯ ` A ) e. NN /\ E. f f : ( 1 ... (♯ ` A ) ) -1-1-onto-> A ) ) )
Theorem	nnf1o 11927	Lemma for sum and product theorems. (Contributed by Jim Kingdon, 15-Aug-2022.)
|- ( ph -> ( M e. NN /\ N e. NN ) )   &    |- ( ph -> F : ( 1 ... M ) -1-1-onto-> A )   &    |- ( ph -> G : ( 1 ... N ) -1-1-onto-> A )   =>    |- ( ph -> N = M )
Theorem	sumrbdclem 11928*	Lemma for sumrbdc 11930. (Contributed by Mario Carneiro, 12-Aug-2013.) (Revised by Jim Kingdon, 8-Apr-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ph -> N e. ( ZZ>= ` M ) )   =>    |- ( ( ph /\ A C_ ( ZZ>= ` N ) ) -> ( seq M ( + , F ) |` ( ZZ>= ` N ) ) = seq N ( + , F ) )
Theorem	fsum3cvg 11929*	The sequence of partial sums of a finite sum converges to the whole sum. (Contributed by Mario Carneiro, 20-Apr-2014.) (Revised by Jim Kingdon, 12-Nov-2022.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ph -> A C_ ( M ... N ) )   =>    |- ( ph -> seq M ( + , F ) ~~> ( seq M ( + , F ) ` N ) )
Theorem	sumrbdc 11930*	Rebase the starting point of a sum. (Contributed by Mario Carneiro, 14-Jul-2013.) (Revised by Jim Kingdon, 9-Apr-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   &    |- ( ph -> A C_ ( ZZ>= ` M ) )   &    |- ( ph -> A C_ ( ZZ>= ` N ) )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ( ph /\ k e. ( ZZ>= ` N ) ) -> DECID k e. A )   =>    |- ( ph -> ( seq M ( + , F ) ~~> C <-> seq N ( + , F ) ~~> C ) )
Theorem	summodclem3 11931*	Lemma for summodc 11934. (Contributed by Mario Carneiro, 29-Mar-2014.) (Revised by Jim Kingdon, 9-Apr-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ph -> ( M e. NN /\ N e. NN ) )   &    |- ( ph -> f : ( 1 ... M ) -1-1-onto-> A )   &    |- ( ph -> K : ( 1 ... N ) -1-1-onto-> A )   &    |- G = ( n e. NN |-> if ( n <_ M , [_ ( f ` n ) / k ]_ B , 0 ) )   &    |- H = ( n e. NN |-> if ( n <_ N , [_ ( K ` n ) / k ]_ B , 0 ) )   =>    |- ( ph -> ( seq 1 ( + , G ) ` M ) = ( seq 1 ( + , H ) ` N ) )
Theorem	summodclem2a 11932*	Lemma for summodc 11934. (Contributed by Mario Carneiro, 3-Apr-2014.) (Revised by Jim Kingdon, 9-Apr-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- G = ( n e. NN |-> if ( n <_ (♯ ` A ) , [_ ( f ` n ) / k ]_ B , 0 ) )   &    |- H = ( n e. NN |-> if ( n <_ N , [_ ( K ` n ) / k ]_ B , 0 ) )   &    |- ( ph -> N e. NN )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> A C_ ( ZZ>= ` M ) )   &    |- ( ph -> f : ( 1 ... N ) -1-1-onto-> A )   &    |- ( ph -> K Isom < , < ( ( 1 ... (♯ ` A ) ) , A ) )   =>    |- ( ph -> seq M ( + , F ) ~~> ( seq 1 ( + , G ) ` N ) )
Theorem	summodclem2 11933*	Lemma for summodc 11934. (Contributed by Mario Carneiro, 3-Apr-2014.) (Revised by Jim Kingdon, 4-May-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- G = ( n e. NN |-> if ( n <_ (♯ ` A ) , [_ ( f ` n ) / k ]_ B , 0 ) )   =>    |- ( ( ph /\ E. m e. ZZ ( A C_ ( ZZ>= ` m ) /\ A. j e. ( ZZ>= ` m )DECID j e. A /\ seq m ( + , F ) ~~> x ) ) -> ( E. m e. NN E. f ( f : ( 1 ... m ) -1-1-onto-> A /\ y = ( seq 1 ( + , G ) ` m ) ) -> x = y ) )
Theorem	summodc 11934*	A sum has at most one limit. (Contributed by Mario Carneiro, 3-Apr-2014.) (Revised by Jim Kingdon, 4-May-2023.)
|- F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- G = ( n e. NN |-> if ( n <_ (♯ ` A ) , [_ ( f ` n ) / k ]_ B , 0 ) )   &    |- G = ( n e. NN |-> if ( n <_ (♯ ` A ) , [_ ( f ` n ) / k ]_ B , 0 ) )   =>    |- ( ph -> E* x ( E. m e. ZZ ( A C_ ( ZZ>= ` m ) /\ A. j e. ( ZZ>= ` m )DECID j e. A /\ seq m ( + , F ) ~~> x ) \/ E. m e. NN E. f ( f : ( 1 ... m ) -1-1-onto-> A /\ x = ( seq 1 ( + , G ) ` m ) ) ) )
Theorem	zsumdc 11935*	Series sum with index set a subset of the upper integers. (Contributed by Mario Carneiro, 13-Jun-2019.) (Revised by Jim Kingdon, 8-Apr-2023.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> A C_ Z )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = if ( k e. A , B , 0 ) )   &    |- ( ph -> A. x e. Z DECID x e. A )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> sum_ k e. A B = ( ~~> ` seq M ( + , F ) ) )
Theorem	isum 11936*	Series sum with an upper integer index set (i.e. an infinite series). (Contributed by Mario Carneiro, 15-Jul-2013.) (Revised by Mario Carneiro, 7-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = B )   &    |- ( ( ph /\ k e. Z ) -> B e. CC )   =>    |- ( ph -> sum_ k e. Z B = ( ~~> ` seq M ( + , F ) ) )
Theorem	fsumgcl 11937*	Closure for a function used to describe a sum over a nonempty finite set. (Contributed by Jim Kingdon, 10-Oct-2022.)
|- ( k = ( F ` n ) -> B = C )   &    |- ( ph -> M e. NN )   &    |- ( ph -> F : ( 1 ... M ) -1-1-onto-> A )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ n e. ( 1 ... M ) ) -> ( G ` n ) = C )   =>    |- ( ph -> A. n e. ( 1 ... M ) ( G ` n ) e. CC )
Theorem	fsum3 11938*	The value of a sum over a nonempty finite set. (Contributed by Jim Kingdon, 10-Oct-2022.)
|- ( k = ( F ` n ) -> B = C )   &    |- ( ph -> M e. NN )   &    |- ( ph -> F : ( 1 ... M ) -1-1-onto-> A )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ n e. ( 1 ... M ) ) -> ( G ` n ) = C )   =>    |- ( ph -> sum_ k e. A B = ( seq 1 ( + , ( n e. NN |-> if ( n <_ M , ( G ` n ) , 0 ) ) ) ` M ) )
Theorem	sum0 11939	Any sum over the empty set is zero. (Contributed by Mario Carneiro, 12-Aug-2013.) (Revised by Mario Carneiro, 20-Apr-2014.)
|- sum_ k e. (/) A = 0
Theorem	isumz 11940*	Any sum of zero over a summable set is zero. (Contributed by Mario Carneiro, 12-Aug-2013.) (Revised by Jim Kingdon, 9-Apr-2023.)
|- ( ( ( M e. ZZ /\ A C_ ( ZZ>= ` M ) /\ A. j e. ( ZZ>= ` M )DECID j e. A ) \/ A e. Fin ) -> sum_ k e. A 0 = 0 )
Theorem	fsumf1o 11941*	Re-index a finite sum using a bijection. (Contributed by Mario Carneiro, 20-Apr-2014.)
|- ( k = G -> B = D )   &    |- ( ph -> C e. Fin )   &    |- ( ph -> F : C -1-1-onto-> A )   &    |- ( ( ph /\ n e. C ) -> ( F ` n ) = G )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> sum_ k e. A B = sum_ n e. C D )
Theorem	isumss 11942*	Change the index set to a subset in an upper integer sum. (Contributed by Mario Carneiro, 21-Apr-2014.) (Revised by Jim Kingdon, 21-Sep-2022.)
|- ( ph -> A C_ B )   &    |- ( ( ph /\ k e. A ) -> C e. CC )   &    |- ( ( ph /\ k e. ( B \ A ) ) -> C = 0 )   &    |- ( ph -> A. j e. ( ZZ>= ` M )DECID j e. A )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> B C_ ( ZZ>= ` M ) )   &    |- ( ph -> A. j e. ( ZZ>= ` M )DECID j e. B )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B C )
Theorem	fisumss 11943*	Change the index set to a subset in a finite sum. (Contributed by Mario Carneiro, 21-Apr-2014.) (Revised by Jim Kingdon, 23-Sep-2022.)
|- ( ph -> A C_ B )   &    |- ( ( ph /\ k e. A ) -> C e. CC )   &    |- ( ( ph /\ k e. ( B \ A ) ) -> C = 0 )   &    |- ( ph -> A. j e. B DECID j e. A )   &    |- ( ph -> B e. Fin )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B C )
Theorem	isumss2 11944*	Change the index set of a sum by adding zeroes. The nonzero elements are in the contained set A and the added zeroes compose the rest of the containing set B which needs to be summable. (Contributed by Mario Carneiro, 15-Jul-2013.) (Revised by Jim Kingdon, 24-Sep-2022.)
|- ( ph -> A C_ B )   &    |- ( ph -> A. j e. B DECID j e. A )   &    |- ( ph -> A. k e. A C e. CC )   &    |- ( ph -> ( ( M e. ZZ /\ B C_ ( ZZ>= ` M ) /\ A. j e. ( ZZ>= ` M )DECID j e. B ) \/ B e. Fin ) )   =>    |- ( ph -> sum_ k e. A C = sum_ k e. B if ( k e. A , C , 0 ) )
Theorem	fsum3cvg2 11945*	The sequence of partial sums of a finite sum converges to the whole sum. (Contributed by Mario Carneiro, 20-Apr-2014.) (Revised by Jim Kingdon, 2-Dec-2022.)
|- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) = if ( k e. A , B , 0 ) )   &    |- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ph -> A C_ ( M ... N ) )   =>    |- ( ph -> seq M ( + , F ) ~~> ( seq M ( + , F ) ` N ) )
Theorem	fsumsersdc 11946*	Special case of series sum over a finite upper integer index set. (Contributed by Mario Carneiro, 26-Jul-2013.) (Revised by Jim Kingdon, 5-May-2023.)
|- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) = if ( k e. A , B , 0 ) )   &    |- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ph -> A C_ ( M ... N ) )   =>    |- ( ph -> sum_ k e. A B = ( seq M ( + , F ) ` N ) )
Theorem	fsum3cvg3 11947*	A finite sum is convergent. (Contributed by Mario Carneiro, 24-Apr-2014.) (Revised by Jim Kingdon, 2-Dec-2022.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> A e. Fin )   &    |- ( ph -> A C_ Z )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> DECID k e. A )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = if ( k e. A , B , 0 ) )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> seq M ( + , F ) e. dom ~~> )
Theorem	fsum3ser 11948*	A finite sum expressed in terms of a partial sum of an infinite series. The recursive definition follows as fsum1 11963 and fsump1 11971, which should make our notation clear and from which, along with closure fsumcl 11951, we will derive the basic properties of finite sums. (Contributed by NM, 11-Dec-2005.) (Revised by Jim Kingdon, 1-Oct-2022.)
|- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> ( F ` k ) = A )   &    |- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. ( ZZ>= ` M ) ) -> A e. CC )   =>    |- ( ph -> sum_ k e. ( M ... N ) A = ( seq M ( + , F ) ` N ) )
Theorem	fsumcl2lem 11949*	- Lemma for finite sum closures. (The "-" before "Lemma" forces the math content to be displayed in the Statement List - NM 11-Feb-2008.) (Contributed by Mario Carneiro, 3-Jun-2014.)
|- ( ph -> S C_ CC )   &    |- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x + y ) e. S )   &    |- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. S )   &    |- ( ph -> A =/= (/) )   =>    |- ( ph -> sum_ k e. A B e. S )
Theorem	fsumcllem 11950*	- Lemma for finite sum closures. (The "-" before "Lemma" forces the math content to be displayed in the Statement List - NM 11-Feb-2008.) (Contributed by NM, 9-Nov-2005.) (Revised by Mario Carneiro, 3-Jun-2014.)
|- ( ph -> S C_ CC )   &    |- ( ( ph /\ ( x e. S /\ y e. S ) ) -> ( x + y ) e. S )   &    |- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. S )   &    |- ( ph -> 0 e. S )   =>    |- ( ph -> sum_ k e. A B e. S )
Theorem	fsumcl 11951*	Closure of a finite sum of complex numbers A ( k ). (Contributed by NM, 9-Nov-2005.) (Revised by Mario Carneiro, 22-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> sum_ k e. A B e. CC )
Theorem	fsumrecl 11952*	Closure of a finite sum of reals. (Contributed by NM, 9-Nov-2005.) (Revised by Mario Carneiro, 22-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. RR )   =>    |- ( ph -> sum_ k e. A B e. RR )
Theorem	fsumzcl 11953*	Closure of a finite sum of integers. (Contributed by NM, 9-Nov-2005.) (Revised by Mario Carneiro, 22-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. ZZ )   =>    |- ( ph -> sum_ k e. A B e. ZZ )
Theorem	fsumnn0cl 11954*	Closure of a finite sum of nonnegative integers. (Contributed by Mario Carneiro, 23-Apr-2015.)
|- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. NN0 )   =>    |- ( ph -> sum_ k e. A B e. NN0 )
Theorem	fsumrpcl 11955*	Closure of a finite sum of positive reals. (Contributed by Mario Carneiro, 3-Jun-2014.)
|- ( ph -> A e. Fin )   &    |- ( ph -> A =/= (/) )   &    |- ( ( ph /\ k e. A ) -> B e. RR+ )   =>    |- ( ph -> sum_ k e. A B e. RR+ )
Theorem	fsumzcl2 11956*	A finite sum with integer summands is an integer. (Contributed by Alexander van der Vekens, 31-Aug-2018.)
|- ( ( A e. Fin /\ A. k e. A B e. ZZ ) -> sum_ k e. A B e. ZZ )
Theorem	fsumadd 11957*	The sum of two finite sums. (Contributed by NM, 14-Nov-2005.) (Revised by Mario Carneiro, 22-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   &    |- ( ( ph /\ k e. A ) -> C e. CC )   =>    |- ( ph -> sum_ k e. A ( B + C ) = ( sum_ k e. A B + sum_ k e. A C ) )
Theorem	fsumsplit 11958*	Split a sum into two parts. (Contributed by Mario Carneiro, 18-Aug-2013.) (Revised by Mario Carneiro, 22-Apr-2014.)
|- ( ph -> ( A i^i B ) = (/) )   &    |- ( ph -> U = ( A u. B ) )   &    |- ( ph -> U e. Fin )   &    |- ( ( ph /\ k e. U ) -> C e. CC )   =>    |- ( ph -> sum_ k e. U C = ( sum_ k e. A C + sum_ k e. B C ) )
Theorem	fsumsplitf 11959*	Split a sum into two parts. A version of fsumsplit 11958 using bound-variable hypotheses instead of distinct variable conditions. (Contributed by Glauco Siliprandi, 5-Apr-2020.)
|- F/ k ph   &    |- ( ph -> ( A i^i B ) = (/) )   &    |- ( ph -> U = ( A u. B ) )   &    |- ( ph -> U e. Fin )   &    |- ( ( ph /\ k e. U ) -> C e. CC )   =>    |- ( ph -> sum_ k e. U C = ( sum_ k e. A C + sum_ k e. B C ) )
Theorem	sumsnf 11960*	A sum of a singleton is the term. A version of sumsn 11962 using bound-variable hypotheses instead of distinct variable conditions. (Contributed by Glauco Siliprandi, 5-Apr-2020.)
|- F/_ k B   &    |- ( k = M -> A = B )   =>    |- ( ( M e. V /\ B e. CC ) -> sum_ k e. { M } A = B )
Theorem	fsumsplitsn 11961*	Separate out a term in a finite sum. (Contributed by Glauco Siliprandi, 5-Apr-2020.)
|- F/ k ph   &    |- F/_ k D   &    |- ( ph -> A e. Fin )   &    |- ( ph -> B e. V )   &    |- ( ph -> -. B e. A )   &    |- ( ( ph /\ k e. A ) -> C e. CC )   &    |- ( k = B -> C = D )   &    |- ( ph -> D e. CC )   =>    |- ( ph -> sum_ k e. ( A u. { B } ) C = ( sum_ k e. A C + D ) )
Theorem	sumsn 11962*	A sum of a singleton is the term. (Contributed by Mario Carneiro, 22-Apr-2014.)
|- ( k = M -> A = B )   =>    |- ( ( M e. V /\ B e. CC ) -> sum_ k e. { M } A = B )
Theorem	fsum1 11963*	The finite sum of A ( k ) from k = M to M (i.e. a sum with only one term) is B i.e. A ( M ). (Contributed by NM, 8-Nov-2005.) (Revised by Mario Carneiro, 21-Apr-2014.)
|- ( k = M -> A = B )   =>    |- ( ( M e. ZZ /\ B e. CC ) -> sum_ k e. ( M ... M ) A = B )
Theorem	sumpr 11964*	A sum over a pair is the sum of the elements. (Contributed by Thierry Arnoux, 12-Dec-2016.)
|- ( k = A -> C = D )   &    |- ( k = B -> C = E )   &    |- ( ph -> ( D e. CC /\ E e. CC ) )   &    |- ( ph -> ( A e. V /\ B e. W ) )   &    |- ( ph -> A =/= B )   =>    |- ( ph -> sum_ k e. { A , B } C = ( D + E ) )
Theorem	sumtp 11965*	A sum over a triple is the sum of the elements. (Contributed by AV, 24-Jul-2020.)
|- ( k = A -> D = E )   &    |- ( k = B -> D = F )   &    |- ( k = C -> D = G )   &    |- ( ph -> ( E e. CC /\ F e. CC /\ G e. CC ) )   &    |- ( ph -> ( A e. V /\ B e. W /\ C e. X ) )   &    |- ( ph -> A =/= B )   &    |- ( ph -> A =/= C )   &    |- ( ph -> B =/= C )   =>    |- ( ph -> sum_ k e. { A , B , C } D = ( ( E + F ) + G ) )
Theorem	sumsns 11966*	A sum of a singleton is the term. (Contributed by Mario Carneiro, 22-Apr-2014.)
|- ( ( M e. V /\ [_ M / k ]_ A e. CC ) -> sum_ k e. { M } A = [_ M / k ]_ A )
Theorem	fsumm1 11967*	Separate out the last term in a finite sum. (Contributed by Mario Carneiro, 26-Apr-2014.)
|- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. ( M ... N ) ) -> A e. CC )   &    |- ( k = N -> A = B )   =>    |- ( ph -> sum_ k e. ( M ... N ) A = ( sum_ k e. ( M ... ( N - 1 ) ) A + B ) )
Theorem	fzosump1 11968*	Separate out the last term in a finite sum. (Contributed by Mario Carneiro, 13-Apr-2016.)
|- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. ( M ... N ) ) -> A e. CC )   &    |- ( k = N -> A = B )   =>    |- ( ph -> sum_ k e. ( M..^ ( N + 1 ) ) A = ( sum_ k e. ( M..^ N ) A + B ) )
Theorem	fsum1p 11969*	Separate out the first term in a finite sum. (Contributed by NM, 3-Jan-2006.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. ( M ... N ) ) -> A e. CC )   &    |- ( k = M -> A = B )   =>    |- ( ph -> sum_ k e. ( M ... N ) A = ( B + sum_ k e. ( ( M + 1 ) ... N ) A ) )
Theorem	fsumsplitsnun 11970*	Separate out a term in a finite sum by splitting the sum into two parts. (Contributed by Alexander van der Vekens, 1-Sep-2018.) (Revised by AV, 17-Dec-2021.)
|- ( ( A e. Fin /\ ( Z e. V /\ Z e/ A ) /\ A. k e. ( A u. { Z } ) B e. ZZ ) -> sum_ k e. ( A u. { Z } ) B = ( sum_ k e. A B + [_ Z / k ]_ B ) )
Theorem	fsump1 11971*	The addition of the next term in a finite sum of A ( k ) is the current term plus B i.e. A ( N + 1 ). (Contributed by NM, 4-Nov-2005.) (Revised by Mario Carneiro, 21-Apr-2014.)
|- ( ph -> N e. ( ZZ>= ` M ) )   &    |- ( ( ph /\ k e. ( M ... ( N + 1 ) ) ) -> A e. CC )   &    |- ( k = ( N + 1 ) -> A = B )   =>    |- ( ph -> sum_ k e. ( M ... ( N + 1 ) ) A = ( sum_ k e. ( M ... N ) A + B ) )
Theorem	isumclim 11972*	An infinite sum equals the value its series converges to. (Contributed by NM, 25-Dec-2005.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) ~~> B )   =>    |- ( ph -> sum_ k e. Z A = B )
Theorem	isumclim2 11973*	A converging series converges to its infinite sum. (Contributed by NM, 2-Jan-2006.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   =>    |- ( ph -> seq M ( + , F ) ~~> sum_ k e. Z A )
Theorem	isumclim3 11974*	The sequence of partial finite sums of a converging infinite series converges to the infinite sum of the series. Note that j must not occur in A. (Contributed by NM, 9-Jan-2006.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> F e. dom ~~> )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ( ph /\ j e. Z ) -> ( F ` j ) = sum_ k e. ( M ... j ) A )   =>    |- ( ph -> F ~~> sum_ k e. Z A )
Theorem	sumnul 11975*	The sum of a non-convergent infinite series evaluates to the empty set. (Contributed by Paul Chapman, 4-Nov-2007.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> -. seq M ( + , F ) e. dom ~~> )   =>    |- ( ph -> sum_ k e. Z A = (/) )
Theorem	isumcl 11976*	The sum of a converging infinite series is a complex number. (Contributed by NM, 13-Dec-2005.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   =>    |- ( ph -> sum_ k e. Z A e. CC )
Theorem	isummulc2 11977*	An infinite sum multiplied by a constant. (Contributed by NM, 12-Nov-2005.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ph -> B e. CC )   =>    |- ( ph -> ( B x. sum_ k e. Z A ) = sum_ k e. Z ( B x. A ) )
Theorem	isummulc1 11978*	An infinite sum multiplied by a constant. (Contributed by NM, 13-Nov-2005.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ph -> B e. CC )   =>    |- ( ph -> ( sum_ k e. Z A x. B ) = sum_ k e. Z ( A x. B ) )
Theorem	isumdivapc 11979*	An infinite sum divided by a constant. (Contributed by NM, 2-Jan-2006.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ph -> B e. CC )   &    |- ( ph -> B # 0 )   =>    |- ( ph -> ( sum_ k e. Z A / B ) = sum_ k e. Z ( A / B ) )
Theorem	isumrecl 11980*	The sum of a converging infinite real series is a real number. (Contributed by Mario Carneiro, 24-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. RR )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   =>    |- ( ph -> sum_ k e. Z A e. RR )
Theorem	isumge0 11981*	An infinite sum of nonnegative terms is nonnegative. (Contributed by Mario Carneiro, 28-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. RR )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ( ph /\ k e. Z ) -> 0 <_ A )   =>    |- ( ph -> 0 <_ sum_ k e. Z A )
Theorem	isumadd 11982*	Addition of infinite sums. (Contributed by Mario Carneiro, 18-Aug-2013.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = A )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ( ph /\ k e. Z ) -> ( G ` k ) = B )   &    |- ( ( ph /\ k e. Z ) -> B e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ph -> seq M ( + , G ) e. dom ~~> )   =>    |- ( ph -> sum_ k e. Z ( A + B ) = ( sum_ k e. Z A + sum_ k e. Z B ) )
Theorem	sumsplitdc 11983*	Split a sum into two parts. (Contributed by Mario Carneiro, 18-Aug-2013.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> ( A i^i B ) = (/) )   &    |- ( ph -> ( A u. B ) C_ Z )   &    |- ( ( ph /\ k e. Z ) -> DECID k e. A )   &    |- ( ( ph /\ k e. Z ) -> DECID k e. B )   &    |- ( ( ph /\ k e. Z ) -> ( F ` k ) = if ( k e. A , C , 0 ) )   &    |- ( ( ph /\ k e. Z ) -> ( G ` k ) = if ( k e. B , C , 0 ) )   &    |- ( ( ph /\ k e. ( A u. B ) ) -> C e. CC )   &    |- ( ph -> seq M ( + , F ) e. dom ~~> )   &    |- ( ph -> seq M ( + , G ) e. dom ~~> )   =>    |- ( ph -> sum_ k e. ( A u. B ) C = ( sum_ k e. A C + sum_ k e. B C ) )
Theorem	fsump1i 11984*	Optimized version of fsump1 11971 for making sums of a concrete number of terms. (Contributed by Mario Carneiro, 23-Apr-2014.)
|- Z = ( ZZ>= ` M )   &    |- N = ( K + 1 )   &    |- ( k = N -> A = B )   &    |- ( ( ph /\ k e. Z ) -> A e. CC )   &    |- ( ph -> ( K e. Z /\ sum_ k e. ( M ... K ) A = S ) )   &    |- ( ph -> ( S + B ) = T )   =>    |- ( ph -> ( N e. Z /\ sum_ k e. ( M ... N ) A = T ) )
Theorem	fsum2dlemstep 11985*	Lemma for fsum2d 11986- induction step. (Contributed by Mario Carneiro, 23-Apr-2014.) (Revised by Jim Kingdon, 8-Oct-2022.)
|- ( z = <. j , k >. -> D = C )   &    |- ( ph -> A e. Fin )   &    |- ( ( ph /\ j e. A ) -> B e. Fin )   &    |- ( ( ph /\ ( j e. A /\ k e. B ) ) -> C e. CC )   &    |- ( ph -> -. y e. x )   &    |- ( ph -> ( x u. { y } ) C_ A )   &    |- ( ph -> x e. Fin )   &    |- ( ps <-> sum_ j e. x sum_ k e. B C = sum_ z e. U_ j e. x ( { j } X. B ) D )   =>    |- ( ( ph /\ ps ) -> sum_ j e. ( x u. { y } ) sum_ k e. B C = sum_ z e. U_ j e. ( x u. { y } ) ( { j } X. B ) D )
Theorem	fsum2d 11986*	Write a double sum as a sum over a two-dimensional region. Note that B ( j ) is a function of j. (Contributed by Mario Carneiro, 27-Apr-2014.)
|- ( z = <. j , k >. -> D = C )   &    |- ( ph -> A e. Fin )   &    |- ( ( ph /\ j e. A ) -> B e. Fin )   &    |- ( ( ph /\ ( j e. A /\ k e. B ) ) -> C e. CC )   =>    |- ( ph -> sum_ j e. A sum_ k e. B C = sum_ z e. U_ j e. A ( { j } X. B ) D )
Theorem	fsumxp 11987*	Combine two sums into a single sum over the cartesian product. (Contributed by Mario Carneiro, 23-Apr-2014.)
|- ( z = <. j , k >. -> D = C )   &    |- ( ph -> A e. Fin )   &    |- ( ph -> B e. Fin )   &    |- ( ( ph /\ ( j e. A /\ k e. B ) ) -> C e. CC )   =>    |- ( ph -> sum_ j e. A sum_ k e. B C = sum_ z e. ( A X. B ) D )
Theorem	fsumcnv 11988*	Transform a region of summation by using the converse operation. (Contributed by Mario Carneiro, 23-Apr-2014.)
|- ( x = <. j , k >. -> B = D )   &    |- ( y = <. k , j >. -> C = D )   &    |- ( ph -> A e. Fin )   &    |- ( ph -> Rel A )   &    |- ( ( ph /\ x e. A ) -> B e. CC )   =>    |- ( ph -> sum_ x e. A B = sum_ y e. `' A C )
Theorem	fisumcom2 11989*	Interchange order of summation. Note that B ( j ) and D ( k ) are not necessarily constant expressions. (Contributed by Mario Carneiro, 28-Apr-2014.) (Revised by Mario Carneiro, 8-Apr-2016.) (Proof shortened by JJ, 2-Aug-2021.)
|- ( ph -> A e. Fin )   &    |- ( ph -> C e. Fin )   &    |- ( ( ph /\ j e. A ) -> B e. Fin )   &    |- ( ( ph /\ k e. C ) -> D e. Fin )   &    |- ( ph -> ( ( j e. A /\ k e. B ) <-> ( k e. C /\ j e. D ) ) )   &    |- ( ( ph /\ ( j e. A /\ k e. B ) ) -> E e. CC )   =>    |- ( ph -> sum_ j e. A sum_ k e. B E = sum_ k e. C sum_ j e. D E )
Theorem	fsumcom 11990*	Interchange order of summation. (Contributed by NM, 15-Nov-2005.) (Revised by Mario Carneiro, 23-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ph -> B e. Fin )   &    |- ( ( ph /\ ( j e. A /\ k e. B ) ) -> C e. CC )   =>    |- ( ph -> sum_ j e. A sum_ k e. B C = sum_ k e. B sum_ j e. A C )
Theorem	fsum0diaglem 11991*	Lemma for fisum0diag 11992. (Contributed by Mario Carneiro, 28-Apr-2014.) (Revised by Mario Carneiro, 8-Apr-2016.)
|- ( ( j e. ( 0 ... N ) /\ k e. ( 0 ... ( N - j ) ) ) -> ( k e. ( 0 ... N ) /\ j e. ( 0 ... ( N - k ) ) ) )
Theorem	fisum0diag 11992*	Two ways to express "the sum of A ( j , k ) over the triangular region M <_ j, M <_ k, j + k <_ N". (Contributed by NM, 31-Dec-2005.) (Proof shortened by Mario Carneiro, 28-Apr-2014.) (Revised by Mario Carneiro, 8-Apr-2016.)
|- ( ( ph /\ ( j e. ( 0 ... N ) /\ k e. ( 0 ... ( N - j ) ) ) ) -> A e. CC )   &    |- ( ph -> N e. ZZ )   =>    |- ( ph -> sum_ j e. ( 0 ... N ) sum_ k e. ( 0 ... ( N - j ) ) A = sum_ k e. ( 0 ... N ) sum_ j e. ( 0 ... ( N - k ) ) A )
Theorem	mptfzshft 11993*	1-1 onto function in maps-to notation which shifts a finite set of sequential integers. (Contributed by AV, 24-Aug-2019.)
|- ( ph -> K e. ZZ )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   =>    |- ( ph -> ( j e. ( ( M + K ) ... ( N + K ) ) |-> ( j - K ) ) : ( ( M + K ) ... ( N + K ) ) -1-1-onto-> ( M ... N ) )
Theorem	fsumrev 11994*	Reversal of a finite sum. (Contributed by NM, 26-Nov-2005.) (Revised by Mario Carneiro, 24-Apr-2014.)
|- ( ph -> K e. ZZ )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   &    |- ( ( ph /\ j e. ( M ... N ) ) -> A e. CC )   &    |- ( j = ( K - k ) -> A = B )   =>    |- ( ph -> sum_ j e. ( M ... N ) A = sum_ k e. ( ( K - N ) ... ( K - M ) ) B )
Theorem	fsumshft 11995*	Index shift of a finite sum. (Contributed by NM, 27-Nov-2005.) (Revised by Mario Carneiro, 24-Apr-2014.) (Proof shortened by AV, 8-Sep-2019.)
|- ( ph -> K e. ZZ )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   &    |- ( ( ph /\ j e. ( M ... N ) ) -> A e. CC )   &    |- ( j = ( k - K ) -> A = B )   =>    |- ( ph -> sum_ j e. ( M ... N ) A = sum_ k e. ( ( M + K ) ... ( N + K ) ) B )
Theorem	fsumshftm 11996*	Negative index shift of a finite sum. (Contributed by NM, 28-Nov-2005.) (Revised by Mario Carneiro, 24-Apr-2014.)
|- ( ph -> K e. ZZ )   &    |- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   &    |- ( ( ph /\ j e. ( M ... N ) ) -> A e. CC )   &    |- ( j = ( k + K ) -> A = B )   =>    |- ( ph -> sum_ j e. ( M ... N ) A = sum_ k e. ( ( M - K ) ... ( N - K ) ) B )
Theorem	fisumrev2 11997*	Reversal of a finite sum. (Contributed by NM, 27-Nov-2005.) (Revised by Mario Carneiro, 13-Apr-2016.)
|- ( ph -> M e. ZZ )   &    |- ( ph -> N e. ZZ )   &    |- ( ( ph /\ j e. ( M ... N ) ) -> A e. CC )   &    |- ( j = ( ( M + N ) - k ) -> A = B )   =>    |- ( ph -> sum_ j e. ( M ... N ) A = sum_ k e. ( M ... N ) B )
Theorem	fisum0diag2 11998*	Two ways to express "the sum of A ( j , k ) over the triangular region 0 <_ j, 0 <_ k, j + k <_ N". (Contributed by Mario Carneiro, 21-Jul-2014.)
|- ( x = k -> B = A )   &    |- ( x = ( k - j ) -> B = C )   &    |- ( ( ph /\ ( j e. ( 0 ... N ) /\ k e. ( 0 ... ( N - j ) ) ) ) -> A e. CC )   &    |- ( ph -> N e. ZZ )   =>    |- ( ph -> sum_ j e. ( 0 ... N ) sum_ k e. ( 0 ... ( N - j ) ) A = sum_ k e. ( 0 ... N ) sum_ j e. ( 0 ... k ) C )
Theorem	fsummulc2 11999*	A finite sum multiplied by a constant. (Contributed by NM, 12-Nov-2005.) (Revised by Mario Carneiro, 24-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ph -> C e. CC )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> ( C x. sum_ k e. A B ) = sum_ k e. A ( C x. B ) )
Theorem	fsummulc1 12000*	A finite sum multiplied by a constant. (Contributed by NM, 13-Nov-2005.) (Revised by Mario Carneiro, 24-Apr-2014.)
|- ( ph -> A e. Fin )   &    |- ( ph -> C e. CC )   &    |- ( ( ph /\ k e. A ) -> B e. CC )   =>    |- ( ph -> ( sum_ k e. A B x. C ) = sum_ k e. A ( B x. C ) )