P. 61 of Theorem List - Intuitionistic Logic Explorer

Theorem List for Intuitionistic Logic Explorer - 6001-6100   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	moriotass 6001*	Restriction of a unique element to a smaller class. (Contributed by NM, 19-Feb-2006.) (Revised by NM, 16-Jun-2017.)
|- ( ( A C_ B /\ E. x e. A ph /\ E* x e. B ph ) -> ( iota_ x e. A ph ) = ( iota_ x e. B ph ) )
Theorem	snriota 6002	A restricted class abstraction with a unique member can be expressed as a singleton. (Contributed by NM, 30-May-2006.)
|- ( E! x e. A ph -> { x e. A | ph } = { ( iota_ x e. A ph ) } )
Theorem	eusvobj2 6003*	Specify the same property in two ways when class B ( y ) is single-valued. (Contributed by NM, 1-Nov-2010.) (Proof shortened by Mario Carneiro, 24-Dec-2016.)
|- B e. _V   =>    |- ( E! x E. y e. A x = B -> ( E. y e. A x = B <-> A. y e. A x = B ) )
Theorem	eusvobj1 6004*	Specify the same object in two ways when class B ( y ) is single-valued. (Contributed by NM, 1-Nov-2010.) (Proof shortened by Mario Carneiro, 19-Nov-2016.)
|- B e. _V   =>    |- ( E! x E. y e. A x = B -> ( iota x E. y e. A x = B ) = ( iota x A. y e. A x = B ) )
Theorem	f1ofveu 6005*	There is one domain element for each value of a one-to-one onto function. (Contributed by NM, 26-May-2006.)
|- ( ( F : A -1-1-onto-> B /\ C e. B ) -> E! x e. A ( F ` x ) = C )
Theorem	f1ocnvfv3 6006*	Value of the converse of a one-to-one onto function. (Contributed by NM, 26-May-2006.) (Proof shortened by Mario Carneiro, 24-Dec-2016.)
|- ( ( F : A -1-1-onto-> B /\ C e. B ) -> ( `' F ` C ) = ( iota_ x e. A ( F ` x ) = C ) )
Theorem	riotaund 6007*	Restricted iota equals the empty set when not meaningful. (Contributed by NM, 16-Jan-2012.) (Revised by Mario Carneiro, 15-Oct-2016.) (Revised by NM, 13-Sep-2018.)
|- ( -. E! x e. A ph -> ( iota_ x e. A ph ) = (/) )
Theorem	acexmidlema 6008*	Lemma for acexmid 6016. (Contributed by Jim Kingdon, 6-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( { (/) } e. A -> ph )
Theorem	acexmidlemb 6009*	Lemma for acexmid 6016. (Contributed by Jim Kingdon, 6-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( (/) e. B -> ph )
Theorem	acexmidlemph 6010*	Lemma for acexmid 6016. (Contributed by Jim Kingdon, 6-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( ph -> A = B )
Theorem	acexmidlemab 6011*	Lemma for acexmid 6016. (Contributed by Jim Kingdon, 6-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( ( ( iota_ v e. A E. u e. y ( A e. u /\ v e. u ) ) = (/) /\ ( iota_ v e. B E. u e. y ( B e. u /\ v e. u ) ) = { (/) } ) -> -. ph )
Theorem	acexmidlemcase 6012*	Lemma for acexmid 6016. Here we divide the proof into cases (based on the disjunction implicit in an unordered pair, not the sort of case elimination which relies on excluded middle). The cases are (1) the choice function evaluated at A equals { (/) }, (2) the choice function evaluated at B equals (/), and (3) the choice function evaluated at A equals (/) and the choice function evaluated at B equals { (/) }. Because of the way we represent the choice function y, the choice function evaluated at A is ( iota_ v e. A E. u e. y ( A e. u /\ v e. u ) ) and the choice function evaluated at B is ( iota_ v e. B E. u e. y ( B e. u /\ v e. u ) ). Other than the difference in notation these work just as ( y ` A ) and ( y ` B ) would if y were a function as defined by df-fun 5328. Although it isn't exactly about the division into cases, it is also convenient for this lemma to also include the step that if the choice function evaluated at A equals { (/) }, then { (/) } e. A and likewise for B. (Contributed by Jim Kingdon, 7-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( A. z e. C E! v e. z E. u e. y ( z e. u /\ v e. u ) -> ( { (/) } e. A \/ (/) e. B \/ ( ( iota_ v e. A E. u e. y ( A e. u /\ v e. u ) ) = (/) /\ ( iota_ v e. B E. u e. y ( B e. u /\ v e. u ) ) = { (/) } ) ) )
Theorem	acexmidlem1 6013*	Lemma for acexmid 6016. List the cases identified in acexmidlemcase 6012 and hook them up to the lemmas which handle each case. (Contributed by Jim Kingdon, 7-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( A. z e. C E! v e. z E. u e. y ( z e. u /\ v e. u ) -> ( ph \/ -. ph ) )
Theorem	acexmidlem2 6014*	Lemma for acexmid 6016. This builds on acexmidlem1 6013 by noting that every element of C is inhabited. (Note that y is not quite a function in the df-fun 5328 sense because it uses ordered pairs as described in opthreg 4654 rather than df-op 3678). The set A is also found in onsucelsucexmidlem 4627. (Contributed by Jim Kingdon, 5-Aug-2019.)
|- A = { x e. { (/) , { (/) } } | ( x = (/) \/ ph ) }   &    |- B = { x e. { (/) , { (/) } } | ( x = { (/) } \/ ph ) }   &    |- C = { A , B }   =>    |- ( A. z e. C A. w e. z E! v e. z E. u e. y ( z e. u /\ v e. u ) -> ( ph \/ -. ph ) )
Theorem	acexmidlemv 6015*	Lemma for acexmid 6016. This is acexmid 6016 with additional disjoint variable conditions, most notably between ph and x. (Contributed by Jim Kingdon, 6-Aug-2019.)
|- E. y A. z e. x A. w e. z E! v e. z E. u e. y ( z e. u /\ v e. u )   =>    |- ( ph \/ -. ph )
Theorem	acexmid 6016*	The axiom of choice implies excluded middle. Theorem 1.3 in [Bauer] p. 483. The statement of the axiom of choice given here is ac2 in the Metamath Proof Explorer (version of 3-Aug-2019). In particular, note that the choice function y provides a value when z is inhabited (as opposed to nonempty as in some statements of the axiom of choice). Essentially the same proof can also be found at "The axiom of choice implies instances of EM", [Crosilla], p. "Set-theoretic principles incompatible with intuitionistic logic". Often referred to as Diaconescu's theorem, or Diaconescu-Goodman-Myhill theorem, after Radu Diaconescu who discovered it in 1975 in the framework of topos theory and N. D. Goodman and John Myhill in 1978 in the framework of set theory (although it already appeared as an exercise in Errett Bishop's book Foundations of Constructive Analysis from 1967). For this theorem stated using the df-ac 7420 and df-exmid 4285 syntaxes, see exmidac 7423. (Contributed by Jim Kingdon, 4-Aug-2019.)
|- E. y A. z e. x A. w e. z E! v e. z E. u e. y ( z e. u /\ v e. u )   =>    |- ( ph \/ -. ph )
2.6.11  Operations
Syntax	co 6017	Extend class notation to include the value of an operation F (such as + ) for two arguments A and B. Note that the syntax is simply three class symbols in a row surrounded by parentheses. Since operation values are the only possible class expressions consisting of three class expressions in a row surrounded by parentheses, the syntax is unambiguous.
class ( A F B )
Syntax	coprab 6018	Extend class notation to include class abstraction (class builder) of nested ordered pairs.
class { <. <. x , y >. , z >. | ph }
Syntax	cmpo 6019	Extend the definition of a class to include maps-to notation for defining an operation via a rule.
class ( x e. A , y e. B |-> C )
Definition	df-ov 6020	Define the value of an operation. Definition of operation value in [Enderton] p. 79. Note that the syntax is simply three class expressions in a row bracketed by parentheses. There are no restrictions of any kind on what those class expressions may be, although only certain kinds of class expressions - a binary operation F and its arguments A and B- will be useful for proving meaningful theorems. For example, if class F is the operation + and arguments A and B are 3 and 2 , the expression ( 3 + 2 ) can be proved to equal 5 . This definition is well-defined, although not very meaningful, when classes A and/or B are proper classes (i.e. are not sets); see ovprc1 6054 and ovprc2 6055. On the other hand, we often find uses for this definition when F is a proper class. F is normally equal to a class of nested ordered pairs of the form defined by df-oprab 6021. (Contributed by NM, 28-Feb-1995.)
|- ( A F B ) = ( F ` <. A , B >. )
Definition	df-oprab 6021*	Define the class abstraction (class builder) of a collection of nested ordered pairs (for use in defining operations). This is a special case of Definition 4.16 of [TakeutiZaring] p. 14. Normally x, y, and z are distinct, although the definition doesn't strictly require it. See df-ov 6020 for the value of an operation. The brace notation is called "class abstraction" by Quine; it is also called a "class builder" in the literature. The value of the most common operation class builder is given by ovmpo 6156. (Contributed by NM, 12-Mar-1995.)
|- { <. <. x , y >. , z >. | ph } = { w | E. x E. y E. z ( w = <. <. x , y >. , z >. /\ ph ) }
Definition	df-mpo 6022*	Define maps-to notation for defining an operation via a rule. Read as "the operation defined by the map from x , y (in A X. B) to B ( x , y )". An extension of df-mpt 4152 for two arguments. (Contributed by NM, 17-Feb-2008.)
|- ( x e. A , y e. B |-> C ) = { <. <. x , y >. , z >. | ( ( x e. A /\ y e. B ) /\ z = C ) }
Theorem	oveq 6023	Equality theorem for operation value. (Contributed by NM, 28-Feb-1995.)
|- ( F = G -> ( A F B ) = ( A G B ) )
Theorem	oveq1 6024	Equality theorem for operation value. (Contributed by NM, 28-Feb-1995.)
|- ( A = B -> ( A F C ) = ( B F C ) )
Theorem	oveq2 6025	Equality theorem for operation value. (Contributed by NM, 28-Feb-1995.)
|- ( A = B -> ( C F A ) = ( C F B ) )
Theorem	oveq12 6026	Equality theorem for operation value. (Contributed by NM, 16-Jul-1995.)
|- ( ( A = B /\ C = D ) -> ( A F C ) = ( B F D ) )
Theorem	oveq1i 6027	Equality inference for operation value. (Contributed by NM, 28-Feb-1995.)
|- A = B   =>    |- ( A F C ) = ( B F C )
Theorem	oveq2i 6028	Equality inference for operation value. (Contributed by NM, 28-Feb-1995.)
|- A = B   =>    |- ( C F A ) = ( C F B )
Theorem	oveq12i 6029	Equality inference for operation value. (Contributed by NM, 28-Feb-1995.) (Proof shortened by Andrew Salmon, 22-Oct-2011.)
|- A = B   &    |- C = D   =>    |- ( A F C ) = ( B F D )
Theorem	oveqi 6030	Equality inference for operation value. (Contributed by NM, 24-Nov-2007.)
|- A = B   =>    |- ( C A D ) = ( C B D )
Theorem	oveq123i 6031	Equality inference for operation value. (Contributed by FL, 11-Jul-2010.)
|- A = C   &    |- B = D   &    |- F = G   =>    |- ( A F B ) = ( C G D )
Theorem	oveq1d 6032	Equality deduction for operation value. (Contributed by NM, 13-Mar-1995.)
|- ( ph -> A = B )   =>    |- ( ph -> ( A F C ) = ( B F C ) )
Theorem	oveq2d 6033	Equality deduction for operation value. (Contributed by NM, 13-Mar-1995.)
|- ( ph -> A = B )   =>    |- ( ph -> ( C F A ) = ( C F B ) )
Theorem	oveqd 6034	Equality deduction for operation value. (Contributed by NM, 9-Sep-2006.)
|- ( ph -> A = B )   =>    |- ( ph -> ( C A D ) = ( C B D ) )
Theorem	oveq12d 6035	Equality deduction for operation value. (Contributed by NM, 13-Mar-1995.) (Proof shortened by Andrew Salmon, 22-Oct-2011.)
|- ( ph -> A = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> ( A F C ) = ( B F D ) )
Theorem	oveqan12d 6036	Equality deduction for operation value. (Contributed by NM, 10-Aug-1995.)
|- ( ph -> A = B )   &    |- ( ps -> C = D )   =>    |- ( ( ph /\ ps ) -> ( A F C ) = ( B F D ) )
Theorem	oveqan12rd 6037	Equality deduction for operation value. (Contributed by NM, 10-Aug-1995.)
|- ( ph -> A = B )   &    |- ( ps -> C = D )   =>    |- ( ( ps /\ ph ) -> ( A F C ) = ( B F D ) )
Theorem	oveq123d 6038	Equality deduction for operation value. (Contributed by FL, 22-Dec-2008.)
|- ( ph -> F = G )   &    |- ( ph -> A = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> ( A F C ) = ( B G D ) )
Theorem	fvoveq1d 6039	Equality deduction for nested function and operation value. (Contributed by AV, 23-Jul-2022.)
|- ( ph -> A = B )   =>    |- ( ph -> ( F ` ( A O C ) ) = ( F ` ( B O C ) ) )
Theorem	fvoveq1 6040	Equality theorem for nested function and operation value. Closed form of fvoveq1d 6039. (Contributed by AV, 23-Jul-2022.)
|- ( A = B -> ( F ` ( A O C ) ) = ( F ` ( B O C ) ) )
Theorem	ovanraleqv 6041*	Equality theorem for a conjunction with an operation values within a restricted universal quantification. Technical theorem to be used to reduce the size of a significant number of proofs. (Contributed by AV, 13-Aug-2022.)
|- ( B = X -> ( ph <-> ps ) )   =>    |- ( B = X -> ( A. x e. V ( ph /\ ( A .x. B ) = C ) <-> A. x e. V ( ps /\ ( A .x. X ) = C ) ) )
Theorem	imbrov2fvoveq 6042	Equality theorem for nested function and operation value in an implication for a binary relation. Technical theorem to be used to reduce the size of a significant number of proofs. (Contributed by AV, 17-Aug-2022.)
|- ( X = Y -> ( ph <-> ps ) )   =>    |- ( X = Y -> ( ( ph -> ( F ` ( ( G ` X ) .x. O ) ) R A ) <-> ( ps -> ( F ` ( ( G ` Y ) .x. O ) ) R A ) ) )
Theorem	ovrspc2v 6043*	If an operation value is element of a class for all operands of two classes, then the operation value is an element of the class for specific operands of the two classes. (Contributed by Mario Carneiro, 6-Dec-2014.)
|- ( ( ( X e. A /\ Y e. B ) /\ A. x e. A A. y e. B ( x F y ) e. C ) -> ( X F Y ) e. C )
Theorem	oveqrspc2v 6044*	Restricted specialization of operands, using implicit substitution. (Contributed by Mario Carneiro, 6-Dec-2014.)
|- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( x F y ) = ( x G y ) )   =>    |- ( ( ph /\ ( X e. A /\ Y e. B ) ) -> ( X F Y ) = ( X G Y ) )
Theorem	oveqdr 6045	Equality of two operations for any two operands. Useful in proofs using *propd theorems. (Contributed by Mario Carneiro, 29-Jun-2015.)
|- ( ph -> F = G )   =>    |- ( ( ph /\ ps ) -> ( x F y ) = ( x G y ) )
Theorem	nfovd 6046	Deduction version of bound-variable hypothesis builder nfov 6047. (Contributed by NM, 13-Dec-2005.) (Proof shortened by Andrew Salmon, 22-Oct-2011.)
|- ( ph -> F/_ x A )   &    |- ( ph -> F/_ x F )   &    |- ( ph -> F/_ x B )   =>    |- ( ph -> F/_ x ( A F B ) )
Theorem	nfov 6047	Bound-variable hypothesis builder for operation value. (Contributed by NM, 4-May-2004.)
|- F/_ x A   &    |- F/_ x F   &    |- F/_ x B   =>    |- F/_ x ( A F B )
Theorem	oprabidlem 6048*	Slight elaboration of exdistrfor 1848. A lemma for oprabid 6049. (Contributed by Jim Kingdon, 15-Jan-2019.)
|- ( E. x E. y ( x = z /\ ps ) -> E. x ( x = z /\ E. y ps ) )
Theorem	oprabid 6049	The law of concretion. Special case of Theorem 9.5 of [Quine] p. 61. Although this theorem would be useful with a distinct variable condition between x, y, and z, we use ax-bndl 1557 to eliminate that constraint. (Contributed by Mario Carneiro, 20-Mar-2013.)
|- ( <. <. x , y >. , z >. e. { <. <. x , y >. , z >. | ph } <-> ph )
Theorem	fnovex 6050	The result of an operation is a set. (Contributed by Jim Kingdon, 15-Jan-2019.)
|- ( ( F Fn ( C X. D ) /\ A e. C /\ B e. D ) -> ( A F B ) e. _V )
Theorem	ovexg 6051	Evaluating a set operation at two sets gives a set. (Contributed by Jim Kingdon, 19-Aug-2021.)
|- ( ( A e. V /\ F e. W /\ B e. X ) -> ( A F B ) e. _V )
Theorem	ovssunirng 6052	The result of an operation value is always a subset of the union of the range. (Contributed by Mario Carneiro, 12-Jan-2017.)
|- ( ( X e. V /\ Y e. W ) -> ( X F Y ) C_ U. ran F )
Theorem	ovprc 6053	The value of an operation when the one of the arguments is a proper class. Note: this theorem is dependent on our particular definitions of operation value, function value, and ordered pair. (Contributed by Mario Carneiro, 26-Apr-2015.)
|- Rel dom F   =>    |- ( -. ( A e. _V /\ B e. _V ) -> ( A F B ) = (/) )
Theorem	ovprc1 6054	The value of an operation when the first argument is a proper class. (Contributed by NM, 16-Jun-2004.)
|- Rel dom F   =>    |- ( -. A e. _V -> ( A F B ) = (/) )
Theorem	ovprc2 6055	The value of an operation when the second argument is a proper class. (Contributed by Mario Carneiro, 26-Apr-2015.)
|- Rel dom F   =>    |- ( -. B e. _V -> ( A F B ) = (/) )
Theorem	csbov123g 6056	Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005.) (Proof shortened by Mario Carneiro, 5-Dec-2016.)
|- ( A e. D -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B [_ A / x ]_ F [_ A / x ]_ C ) )
Theorem	csbov12g 6057*	Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005.)
|- ( A e. V -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B F [_ A / x ]_ C ) )
Theorem	csbov1g 6058*	Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005.)
|- ( A e. V -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B F C ) )
Theorem	csbov2g 6059*	Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005.)
|- ( A e. V -> [_ A / x ]_ ( B F C ) = ( B F [_ A / x ]_ C ) )
Theorem	rspceov 6060*	A frequently used special case of rspc2ev 2925 for operation values. (Contributed by NM, 21-Mar-2007.)
|- ( ( C e. A /\ D e. B /\ S = ( C F D ) ) -> E. x e. A E. y e. B S = ( x F y ) )
Theorem	elovimad 6061	Elementhood of the image set of an operation value. (Contributed by Thierry Arnoux, 13-Mar-2017.)
|- ( ph -> A e. C )   &    |- ( ph -> B e. D )   &    |- ( ph -> Fun F )   &    |- ( ph -> ( C X. D ) C_ dom F )   =>    |- ( ph -> ( A F B ) e. ( F " ( C X. D ) ) )
Theorem	fnbrovb 6062	Value of a binary operation expressed as a binary relation. See also fnbrfvb 5684 for functions on Cartesian products. (Contributed by BJ, 15-Feb-2022.)
|- ( ( F Fn ( V X. W ) /\ ( A e. V /\ B e. W ) ) -> ( ( A F B ) = C <-> <. A , B >. F C ) )
Theorem	fnotovb 6063	Equivalence of operation value and ordered triple membership, analogous to fnopfvb 5685. (Contributed by NM, 17-Dec-2008.) (Revised by Mario Carneiro, 28-Apr-2015.)
|- ( ( F Fn ( A X. B ) /\ C e. A /\ D e. B ) -> ( ( C F D ) = R <-> <. C , D , R >. e. F ) )
Theorem	opabbrex 6064*	A collection of ordered pairs with an extension of a binary relation is a set. (Contributed by Alexander van der Vekens, 1-Nov-2017.)
|- ( ( V e. _V /\ E e. _V ) -> ( f ( V W E ) p -> th ) )   &    |- ( ( V e. _V /\ E e. _V ) -> { <. f , p >. | th } e. _V )   =>    |- ( ( V e. _V /\ E e. _V ) -> { <. f , p >. | ( f ( V W E ) p /\ ps ) } e. _V )
Theorem	0neqopab 6065	The empty set is never an element in an ordered-pair class abstraction. (Contributed by Alexander van der Vekens, 5-Nov-2017.)
|- -. (/) e. { <. x , y >. | ph }
Theorem	brabvv 6066*	If two classes are in a relationship given by an ordered-pair class abstraction, the classes are sets. (Contributed by Jim Kingdon, 16-Jan-2019.)
|- ( X { <. x , y >. | ph } Y -> ( X e. _V /\ Y e. _V ) )
Theorem	dfoprab2 6067*	Class abstraction for operations in terms of class abstraction of ordered pairs. (Contributed by NM, 12-Mar-1995.)
|- { <. <. x , y >. , z >. | ph } = { <. w , z >. | E. x E. y ( w = <. x , y >. /\ ph ) }
Theorem	reloprab 6068*	An operation class abstraction is a relation. (Contributed by NM, 16-Jun-2004.)
|- Rel { <. <. x , y >. , z >. | ph }
Theorem	nfoprab1 6069	The abstraction variables in an operation class abstraction are not free. (Contributed by NM, 25-Apr-1995.) (Revised by David Abernethy, 19-Jun-2012.)
|- F/_ x { <. <. x , y >. , z >. | ph }
Theorem	nfoprab2 6070	The abstraction variables in an operation class abstraction are not free. (Contributed by NM, 25-Apr-1995.) (Revised by David Abernethy, 30-Jul-2012.)
|- F/_ y { <. <. x , y >. , z >. | ph }
Theorem	nfoprab3 6071	The abstraction variables in an operation class abstraction are not free. (Contributed by NM, 22-Aug-2013.)
|- F/_ z { <. <. x , y >. , z >. | ph }
Theorem	nfoprab 6072*	Bound-variable hypothesis builder for an operation class abstraction. (Contributed by NM, 22-Aug-2013.)
|- F/ w ph   =>    |- F/_ w { <. <. x , y >. , z >. | ph }
Theorem	oprabbid 6073*	Equivalent wff's yield equal operation class abstractions (deduction form). (Contributed by NM, 21-Feb-2004.) (Revised by Mario Carneiro, 24-Jun-2014.)
|- F/ x ph   &    |- F/ y ph   &    |- F/ z ph   &    |- ( ph -> ( ps <-> ch ) )   =>    |- ( ph -> { <. <. x , y >. , z >. | ps } = { <. <. x , y >. , z >. | ch } )
Theorem	oprabbidv 6074*	Equivalent wff's yield equal operation class abstractions (deduction form). (Contributed by NM, 21-Feb-2004.)
|- ( ph -> ( ps <-> ch ) )   =>    |- ( ph -> { <. <. x , y >. , z >. | ps } = { <. <. x , y >. , z >. | ch } )
Theorem	oprabbii 6075*	Equivalent wff's yield equal operation class abstractions. (Contributed by NM, 28-May-1995.) (Revised by David Abernethy, 19-Jun-2012.)
|- ( ph <-> ps )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , z >. | ps }
Theorem	ssoprab2 6076	Equivalence of ordered pair abstraction subclass and implication. Compare ssopab2 4370. (Contributed by FL, 6-Nov-2013.) (Proof shortened by Mario Carneiro, 11-Dec-2016.)
|- ( A. x A. y A. z ( ph -> ps ) -> { <. <. x , y >. , z >. | ph } C_ { <. <. x , y >. , z >. | ps } )
Theorem	ssoprab2b 6077	Equivalence of ordered pair abstraction subclass and implication. Compare ssopab2b 4371. (Contributed by FL, 6-Nov-2013.) (Proof shortened by Mario Carneiro, 11-Dec-2016.)
|- ( { <. <. x , y >. , z >. | ph } C_ { <. <. x , y >. , z >. | ps } <-> A. x A. y A. z ( ph -> ps ) )
Theorem	eqoprab2b 6078	Equivalence of ordered pair abstraction subclass and biconditional. Compare eqopab2b 4374. (Contributed by Mario Carneiro, 4-Jan-2017.)
|- ( { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , z >. | ps } <-> A. x A. y A. z ( ph <-> ps ) )
Theorem	mpoeq123 6079*	An equality theorem for the maps-to notation. (Contributed by Mario Carneiro, 16-Dec-2013.) (Revised by Mario Carneiro, 19-Mar-2015.)
|- ( ( A = D /\ A. x e. A ( B = E /\ A. y e. B C = F ) ) -> ( x e. A , y e. B |-> C ) = ( x e. D , y e. E |-> F ) )
Theorem	mpoeq12 6080*	An equality theorem for the maps-to notation. (Contributed by Mario Carneiro, 16-Dec-2013.)
|- ( ( A = C /\ B = D ) -> ( x e. A , y e. B |-> E ) = ( x e. C , y e. D |-> E ) )
Theorem	mpoeq123dva 6081*	An equality deduction for the maps-to notation. (Contributed by Mario Carneiro, 26-Jan-2017.)
|- ( ph -> A = D )   &    |- ( ( ph /\ x e. A ) -> B = E )   &    |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> C = F )   =>    |- ( ph -> ( x e. A , y e. B |-> C ) = ( x e. D , y e. E |-> F ) )
Theorem	mpoeq123dv 6082*	An equality deduction for the maps-to notation. (Contributed by NM, 12-Sep-2011.)
|- ( ph -> A = D )   &    |- ( ph -> B = E )   &    |- ( ph -> C = F )   =>    |- ( ph -> ( x e. A , y e. B |-> C ) = ( x e. D , y e. E |-> F ) )
Theorem	mpoeq123i 6083	An equality inference for the maps-to notation. (Contributed by NM, 15-Jul-2013.)
|- A = D   &    |- B = E   &    |- C = F   =>    |- ( x e. A , y e. B |-> C ) = ( x e. D , y e. E |-> F )
Theorem	mpoeq3dva 6084*	Slightly more general equality inference for the maps-to notation. (Contributed by NM, 17-Oct-2013.)
|- ( ( ph /\ x e. A /\ y e. B ) -> C = D )   =>    |- ( ph -> ( x e. A , y e. B |-> C ) = ( x e. A , y e. B |-> D ) )
Theorem	mpoeq3ia 6085	An equality inference for the maps-to notation. (Contributed by Mario Carneiro, 16-Dec-2013.)
|- ( ( x e. A /\ y e. B ) -> C = D )   =>    |- ( x e. A , y e. B |-> C ) = ( x e. A , y e. B |-> D )
Theorem	mpoeq3dv 6086*	An equality deduction for the maps-to notation restricted to the value of the operation. (Contributed by SO, 16-Jul-2018.)
|- ( ph -> C = D )   =>    |- ( ph -> ( x e. A , y e. B |-> C ) = ( x e. A , y e. B |-> D ) )
Theorem	nfmpo1 6087	Bound-variable hypothesis builder for an operation in maps-to notation. (Contributed by NM, 27-Aug-2013.)
|- F/_ x ( x e. A , y e. B |-> C )
Theorem	nfmpo2 6088	Bound-variable hypothesis builder for an operation in maps-to notation. (Contributed by NM, 27-Aug-2013.)
|- F/_ y ( x e. A , y e. B |-> C )
Theorem	nfmpo 6089*	Bound-variable hypothesis builder for the maps-to notation. (Contributed by NM, 20-Feb-2013.)
|- F/_ z A   &    |- F/_ z B   &    |- F/_ z C   =>    |- F/_ z ( x e. A , y e. B |-> C )
Theorem	mpo0 6090	A mapping operation with empty domain. (Contributed by Stefan O'Rear, 29-Jan-2015.) (Revised by Mario Carneiro, 15-May-2015.)
|- ( x e. (/) , y e. B |-> C ) = (/)
Theorem	oprab4 6091*	Two ways to state the domain of an operation. (Contributed by FL, 24-Jan-2010.)
|- { <. <. x , y >. , z >. | ( <. x , y >. e. ( A X. B ) /\ ph ) } = { <. <. x , y >. , z >. | ( ( x e. A /\ y e. B ) /\ ph ) }
Theorem	cbvoprab1 6092*	Rule used to change first bound variable in an operation abstraction, using implicit substitution. (Contributed by NM, 20-Dec-2008.) (Revised by Mario Carneiro, 5-Dec-2016.)
|- F/ w ph   &    |- F/ x ps   &    |- ( x = w -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. w , y >. , z >. | ps }
Theorem	cbvoprab2 6093*	Change the second bound variable in an operation abstraction. (Contributed by Jeff Madsen, 11-Jun-2010.) (Revised by Mario Carneiro, 11-Dec-2016.)
|- F/ w ph   &    |- F/ y ps   &    |- ( y = w -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. x , w >. , z >. | ps }
Theorem	cbvoprab12 6094*	Rule used to change first two bound variables in an operation abstraction, using implicit substitution. (Contributed by NM, 21-Feb-2004.) (Proof shortened by Andrew Salmon, 22-Oct-2011.)
|- F/ w ph   &    |- F/ v ph   &    |- F/ x ps   &    |- F/ y ps   &    |- ( ( x = w /\ y = v ) -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. w , v >. , z >. | ps }
Theorem	cbvoprab12v 6095*	Rule used to change first two bound variables in an operation abstraction, using implicit substitution. (Contributed by NM, 8-Oct-2004.)
|- ( ( x = w /\ y = v ) -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. w , v >. , z >. | ps }
Theorem	cbvoprab3 6096*	Rule used to change the third bound variable in an operation abstraction, using implicit substitution. (Contributed by NM, 22-Aug-2013.)
|- F/ w ph   &    |- F/ z ps   &    |- ( z = w -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , w >. | ps }
Theorem	cbvoprab3v 6097*	Rule used to change the third bound variable in an operation abstraction, using implicit substitution. (Contributed by NM, 8-Oct-2004.) (Revised by David Abernethy, 19-Jun-2012.)
|- ( z = w -> ( ph <-> ps ) )   =>    |- { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , w >. | ps }
Theorem	cbvmpox 6098*	Rule to change the bound variable in a maps-to function, using implicit substitution. This version of cbvmpo 6099 allows B to be a function of x. (Contributed by NM, 29-Dec-2014.)
|- F/_ z B   &    |- F/_ x D   &    |- F/_ z C   &    |- F/_ w C   &    |- F/_ x E   &    |- F/_ y E   &    |- ( x = z -> B = D )   &    |- ( ( x = z /\ y = w ) -> C = E )   =>    |- ( x e. A , y e. B |-> C ) = ( z e. A , w e. D |-> E )
Theorem	cbvmpo 6099*	Rule to change the bound variable in a maps-to function, using implicit substitution. (Contributed by NM, 17-Dec-2013.)
|- F/_ z C   &    |- F/_ w C   &    |- F/_ x D   &    |- F/_ y D   &    |- ( ( x = z /\ y = w ) -> C = D )   =>    |- ( x e. A , y e. B |-> C ) = ( z e. A , w e. B |-> D )
Theorem	cbvmpov 6100*	Rule to change the bound variable in a maps-to function, using implicit substitution. With a longer proof analogous to cbvmpt 4184, some distinct variable requirements could be eliminated. (Contributed by NM, 11-Jun-2013.)
|- ( x = z -> C = E )   &    |- ( y = w -> E = D )   =>    |- ( x e. A , y e. B |-> C ) = ( z e. A , w e. B |-> D )