P. 53 of Theorem List - Intuitionistic Logic Explorer

Theorem List for Intuitionistic Logic Explorer - 5201-5300   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	imaundir 5201	The image of a union. (Contributed by Jeff Hoffman, 17-Feb-2008.)
|- ( ( A u. B ) " C ) = ( ( A " C ) u. ( B " C ) )
Theorem	dminss 5202	An upper bound for intersection with a domain. Theorem 40 of [Suppes] p. 66, who calls it "somewhat surprising". (Contributed by NM, 11-Aug-2004.)
|- ( dom R i^i A ) C_ ( `' R " ( R " A ) )
Theorem	imainss 5203	An upper bound for intersection with an image. Theorem 41 of [Suppes] p. 66. (Contributed by NM, 11-Aug-2004.)
|- ( ( R " A ) i^i B ) C_ ( R " ( A i^i ( `' R " B ) ) )
Theorem	inimass 5204	The image of an intersection. (Contributed by Thierry Arnoux, 16-Dec-2017.)
|- ( ( A i^i B ) " C ) C_ ( ( A " C ) i^i ( B " C ) )
Theorem	inimasn 5205	The intersection of the image of singleton. (Contributed by Thierry Arnoux, 16-Dec-2017.)
|- ( C e. V -> ( ( A i^i B ) " { C } ) = ( ( A " { C } ) i^i ( B " { C } ) ) )
Theorem	cnvxp 5206	The converse of a cross product. Exercise 11 of [Suppes] p. 67. (Contributed by NM, 14-Aug-1999.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- `' ( A X. B ) = ( B X. A )
Theorem	xp0 5207	The cross product with the empty set is empty. Part of Theorem 3.13(ii) of [Monk1] p. 37. (Contributed by NM, 12-Apr-2004.)
|- ( A X. (/) ) = (/)
Theorem	xpmlem 5208*	The cross product of inhabited classes is inhabited. (Contributed by Jim Kingdon, 11-Dec-2018.)
|- ( ( E. x x e. A /\ E. y y e. B ) <-> E. z z e. ( A X. B ) )
Theorem	xpm 5209*	The cross product of inhabited classes is inhabited. (Contributed by Jim Kingdon, 13-Dec-2018.)
|- ( ( E. x x e. A /\ E. y y e. B ) <-> E. z z e. ( A X. B ) )
Theorem	xpeq0r 5210	A cross product is empty if at least one member is empty. (Contributed by Jim Kingdon, 12-Dec-2018.)
|- ( ( A = (/) \/ B = (/) ) -> ( A X. B ) = (/) )
Theorem	sqxpeq0 5211	A Cartesian square is empty iff its member is empty. (Contributed by Jim Kingdon, 21-Apr-2023.)
|- ( ( A X. A ) = (/) <-> A = (/) )
Theorem	xpdisj1 5212	Cross products with disjoint sets are disjoint. (Contributed by NM, 13-Sep-2004.)
|- ( ( A i^i B ) = (/) -> ( ( A X. C ) i^i ( B X. D ) ) = (/) )
Theorem	xpdisj2 5213	Cross products with disjoint sets are disjoint. (Contributed by NM, 13-Sep-2004.)
|- ( ( A i^i B ) = (/) -> ( ( C X. A ) i^i ( D X. B ) ) = (/) )
Theorem	xpsndisj 5214	Cross products with two different singletons are disjoint. (Contributed by NM, 28-Jul-2004.)
|- ( B =/= D -> ( ( A X. { B } ) i^i ( C X. { D } ) ) = (/) )
Theorem	djudisj 5215*	Disjoint unions with disjoint index sets are disjoint. (Contributed by Stefan O'Rear, 21-Nov-2014.)
|- ( ( A i^i B ) = (/) -> ( U_ x e. A ( { x } X. C ) i^i U_ y e. B ( { y } X. D ) ) = (/) )
Theorem	resdisj 5216	A double restriction to disjoint classes is the empty set. (Contributed by NM, 7-Oct-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( ( A i^i B ) = (/) -> ( ( C |` A ) |` B ) = (/) )
Theorem	rnxpm 5217*	The range of a cross product. Part of Theorem 3.13(x) of [Monk1] p. 37, with nonempty changed to inhabited. (Contributed by Jim Kingdon, 12-Dec-2018.)
|- ( E. x x e. A -> ran ( A X. B ) = B )
Theorem	dmxpss 5218	The domain of a cross product is a subclass of the first factor. (Contributed by NM, 19-Mar-2007.)
|- dom ( A X. B ) C_ A
Theorem	rnxpss 5219	The range of a cross product is a subclass of the second factor. (Contributed by NM, 16-Jan-2006.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ran ( A X. B ) C_ B
Theorem	dmxpss2 5220	Upper bound for the domain of a binary relation. (Contributed by BJ, 10-Jul-2022.)
|- ( R C_ ( A X. B ) -> dom R C_ A )
Theorem	rnxpss2 5221	Upper bound for the range of a binary relation. (Contributed by BJ, 10-Jul-2022.)
|- ( R C_ ( A X. B ) -> ran R C_ B )
Theorem	rnxpid 5222	The range of a square cross product. (Contributed by FL, 17-May-2010.)
|- ran ( A X. A ) = A
Theorem	ssxpbm 5223*	A cross-product subclass relationship is equivalent to the relationship for its components. (Contributed by Jim Kingdon, 12-Dec-2018.)
|- ( E. x x e. ( A X. B ) -> ( ( A X. B ) C_ ( C X. D ) <-> ( A C_ C /\ B C_ D ) ) )
Theorem	ssxp1 5224*	Cross product subset cancellation. (Contributed by Jim Kingdon, 14-Dec-2018.)
|- ( E. x x e. C -> ( ( A X. C ) C_ ( B X. C ) <-> A C_ B ) )
Theorem	ssxp2 5225*	Cross product subset cancellation. (Contributed by Jim Kingdon, 14-Dec-2018.)
|- ( E. x x e. C -> ( ( C X. A ) C_ ( C X. B ) <-> A C_ B ) )
Theorem	xp11m 5226*	The cross product of inhabited classes is one-to-one. (Contributed by Jim Kingdon, 13-Dec-2018.)
|- ( ( E. x x e. A /\ E. y y e. B ) -> ( ( A X. B ) = ( C X. D ) <-> ( A = C /\ B = D ) ) )
Theorem	xpcanm 5227*	Cancellation law for cross-product. (Contributed by Jim Kingdon, 14-Dec-2018.)
|- ( E. x x e. C -> ( ( C X. A ) = ( C X. B ) <-> A = B ) )
Theorem	xpcan2m 5228*	Cancellation law for cross-product. (Contributed by Jim Kingdon, 14-Dec-2018.)
|- ( E. x x e. C -> ( ( A X. C ) = ( B X. C ) <-> A = B ) )
Theorem	xpexr2m 5229*	If a nonempty cross product is a set, so are both of its components. (Contributed by Jim Kingdon, 14-Dec-2018.)
|- ( ( ( A X. B ) e. C /\ E. x x e. ( A X. B ) ) -> ( A e. _V /\ B e. _V ) )
Theorem	ssrnres 5230	Subset of the range of a restriction. (Contributed by NM, 16-Jan-2006.)
|- ( B C_ ran ( C |` A ) <-> ran ( C i^i ( A X. B ) ) = B )
Theorem	rninxp 5231*	Range of the intersection with a cross product. (Contributed by NM, 17-Jan-2006.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( ran ( C i^i ( A X. B ) ) = B <-> A. y e. B E. x e. A x C y )
Theorem	dminxp 5232*	Domain of the intersection with a cross product. (Contributed by NM, 17-Jan-2006.)
|- ( dom ( C i^i ( A X. B ) ) = A <-> A. x e. A E. y e. B x C y )
Theorem	imainrect 5233	Image of a relation restricted to a rectangular region. (Contributed by Stefan O'Rear, 19-Feb-2015.)
|- ( ( G i^i ( A X. B ) ) " Y ) = ( ( G " ( Y i^i A ) ) i^i B )
Theorem	xpima1 5234	The image by a cross product. (Contributed by Thierry Arnoux, 16-Dec-2017.)
|- ( ( A i^i C ) = (/) -> ( ( A X. B ) " C ) = (/) )
Theorem	xpima2m 5235*	The image by a cross product. (Contributed by Thierry Arnoux, 16-Dec-2017.)
|- ( E. x x e. ( A i^i C ) -> ( ( A X. B ) " C ) = B )
Theorem	xpimasn 5236	The image of a singleton by a cross product. (Contributed by Thierry Arnoux, 14-Jan-2018.)
|- ( X e. A -> ( ( A X. B ) " { X } ) = B )
Theorem	cnvcnv3 5237*	The set of all ordered pairs in a class is the same as the double converse. (Contributed by Mario Carneiro, 16-Aug-2015.)
|- `' `' R = { <. x , y >. | x R y }
Theorem	dfrel2 5238	Alternate definition of relation. Exercise 2 of [TakeutiZaring] p. 25. (Contributed by NM, 29-Dec-1996.)
|- ( Rel R <-> `' `' R = R )
Theorem	dfrel4v 5239*	A relation can be expressed as the set of ordered pairs in it. (Contributed by Mario Carneiro, 16-Aug-2015.)
|- ( Rel R <-> R = { <. x , y >. | x R y } )
Theorem	cnvcnv 5240	The double converse of a class strips out all elements that are not ordered pairs. (Contributed by NM, 8-Dec-2003.)
|- `' `' A = ( A i^i ( _V X. _V ) )
Theorem	cnvcnv2 5241	The double converse of a class equals its restriction to the universe. (Contributed by NM, 8-Oct-2007.)
|- `' `' A = ( A |` _V )
Theorem	cnvcnvss 5242	The double converse of a class is a subclass. Exercise 2 of [TakeutiZaring] p. 25. (Contributed by NM, 23-Jul-2004.)
|- `' `' A C_ A
Theorem	cnveqb 5243	Equality theorem for converse. (Contributed by FL, 19-Sep-2011.)
|- ( ( Rel A /\ Rel B ) -> ( A = B <-> `' A = `' B ) )
Theorem	cnveq0 5244	A relation empty iff its converse is empty. (Contributed by FL, 19-Sep-2011.)
|- ( Rel A -> ( A = (/) <-> `' A = (/) ) )
Theorem	dfrel3 5245	Alternate definition of relation. (Contributed by NM, 14-May-2008.)
|- ( Rel R <-> ( R |` _V ) = R )
Theorem	dmresv 5246	The domain of a universal restriction. (Contributed by NM, 14-May-2008.)
|- dom ( A |` _V ) = dom A
Theorem	rnresv 5247	The range of a universal restriction. (Contributed by NM, 14-May-2008.)
|- ran ( A |` _V ) = ran A
Theorem	dfrn4 5248	Range defined in terms of image. (Contributed by NM, 14-May-2008.)
|- ran A = ( A " _V )
Theorem	csbrng 5249	Distribute proper substitution through the range of a class. (Contributed by Alan Sare, 10-Nov-2012.)
|- ( A e. V -> [_ A / x ]_ ran B = ran [_ A / x ]_ B )
Theorem	rescnvcnv 5250	The restriction of the double converse of a class. (Contributed by NM, 8-Apr-2007.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( `' `' A |` B ) = ( A |` B )
Theorem	cnvcnvres 5251	The double converse of the restriction of a class. (Contributed by NM, 3-Jun-2007.)
|- `' `' ( A |` B ) = ( `' `' A |` B )
Theorem	imacnvcnv 5252	The image of the double converse of a class. (Contributed by NM, 8-Apr-2007.)
|- ( `' `' A " B ) = ( A " B )
Theorem	dmsnm 5253*	The domain of a singleton is inhabited iff the singleton argument is an ordered pair. (Contributed by Jim Kingdon, 15-Dec-2018.)
|- ( A e. ( _V X. _V ) <-> E. x x e. dom { A } )
Theorem	rnsnm 5254*	The range of a singleton is inhabited iff the singleton argument is an ordered pair. (Contributed by Jim Kingdon, 15-Dec-2018.)
|- ( A e. ( _V X. _V ) <-> E. x x e. ran { A } )
Theorem	dmsn0 5255	The domain of the singleton of the empty set is empty. (Contributed by NM, 30-Jan-2004.)
|- dom { (/) } = (/)
Theorem	cnvsn0 5256	The converse of the singleton of the empty set is empty. (Contributed by Mario Carneiro, 30-Aug-2015.)
|- `' { (/) } = (/)
Theorem	dmsn0el 5257	The domain of a singleton is empty if the singleton's argument contains the empty set. (Contributed by NM, 15-Dec-2008.)
|- ( (/) e. A -> dom { A } = (/) )
Theorem	relsn2m 5258*	A singleton is a relation iff it has an inhabited domain. (Contributed by Jim Kingdon, 16-Dec-2018.)
|- A e. _V   =>    |- ( Rel { A } <-> E. x x e. dom { A } )
Theorem	dmsnopg 5259	The domain of a singleton of an ordered pair is the singleton of the first member. (Contributed by Mario Carneiro, 26-Apr-2015.)
|- ( B e. V -> dom { <. A , B >. } = { A } )
Theorem	dmpropg 5260	The domain of an unordered pair of ordered pairs. (Contributed by Mario Carneiro, 26-Apr-2015.)
|- ( ( B e. V /\ D e. W ) -> dom { <. A , B >. , <. C , D >. } = { A , C } )
Theorem	dmsnop 5261	The domain of a singleton of an ordered pair is the singleton of the first member. (Contributed by NM, 30-Jan-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.) (Revised by Mario Carneiro, 26-Apr-2015.)
|- B e. _V   =>    |- dom { <. A , B >. } = { A }
Theorem	dmprop 5262	The domain of an unordered pair of ordered pairs. (Contributed by NM, 13-Sep-2011.)
|- B e. _V   &    |- D e. _V   =>    |- dom { <. A , B >. , <. C , D >. } = { A , C }
Theorem	dmtpop 5263	The domain of an unordered triple of ordered pairs. (Contributed by NM, 14-Sep-2011.)
|- B e. _V   &    |- D e. _V   &    |- F e. _V   =>    |- dom { <. A , B >. , <. C , D >. , <. E , F >. } = { A , C , E }
Theorem	cnvcnvsn 5264	Double converse of a singleton of an ordered pair. (Unlike cnvsn 5270, this does not need any sethood assumptions on A and B.) (Contributed by Mario Carneiro, 26-Apr-2015.)
|- `' `' { <. A , B >. } = `' { <. B , A >. }
Theorem	dmsnsnsng 5265	The domain of the singleton of the singleton of a singleton. (Contributed by Jim Kingdon, 16-Dec-2018.)
|- ( A e. _V -> dom { { { A } } } = { A } )
Theorem	rnsnopg 5266	The range of a singleton of an ordered pair is the singleton of the second member. (Contributed by NM, 24-Jul-2004.) (Revised by Mario Carneiro, 30-Apr-2015.)
|- ( A e. V -> ran { <. A , B >. } = { B } )
Theorem	rnpropg 5267	The range of a pair of ordered pairs is the pair of second members. (Contributed by Thierry Arnoux, 3-Jan-2017.)
|- ( ( A e. V /\ B e. W ) -> ran { <. A , C >. , <. B , D >. } = { C , D } )
Theorem	rnsnop 5268	The range of a singleton of an ordered pair is the singleton of the second member. (Contributed by NM, 24-Jul-2004.) (Revised by Mario Carneiro, 26-Apr-2015.)
|- A e. _V   =>    |- ran { <. A , B >. } = { B }
Theorem	op1sta 5269	Extract the first member of an ordered pair. (See op2nda 5272 to extract the second member and op1stb 4624 for an alternate version.) (Contributed by Raph Levien, 4-Dec-2003.)
|- A e. _V   &    |- B e. _V   =>    |- U. dom { <. A , B >. } = A
Theorem	cnvsn 5270	Converse of a singleton of an ordered pair. (Contributed by NM, 11-May-1998.) (Revised by Mario Carneiro, 26-Apr-2015.)
|- A e. _V   &    |- B e. _V   =>    |- `' { <. A , B >. } = { <. B , A >. }
Theorem	op2ndb 5271	Extract the second member of an ordered pair. Theorem 5.12(ii) of [Monk1] p. 52. (See op1stb 4624 to extract the first member and op2nda 5272 for an alternate version.) (Contributed by NM, 25-Nov-2003.)
|- A e. _V   &    |- B e. _V   =>    |- |^| |^| |^| `' { <. A , B >. } = B
Theorem	op2nda 5272	Extract the second member of an ordered pair. (See op1sta 5269 to extract the first member and op2ndb 5271 for an alternate version.) (Contributed by NM, 17-Feb-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- A e. _V   &    |- B e. _V   =>    |- U. ran { <. A , B >. } = B
Theorem	cnvsng 5273	Converse of a singleton of an ordered pair. (Contributed by NM, 23-Jan-2015.)
|- ( ( A e. V /\ B e. W ) -> `' { <. A , B >. } = { <. B , A >. } )
Theorem	opswapg 5274	Swap the members of an ordered pair. (Contributed by Jim Kingdon, 16-Dec-2018.)
|- ( ( A e. V /\ B e. W ) -> U. `' { <. A , B >. } = <. B , A >. )
Theorem	elxp4 5275	Membership in a cross product. This version requires no quantifiers or dummy variables. See also elxp5 5276. (Contributed by NM, 17-Feb-2004.)
|- ( A e. ( B X. C ) <-> ( A = <. U. dom { A } , U. ran { A } >. /\ ( U. dom { A } e. B /\ U. ran { A } e. C ) ) )
Theorem	elxp5 5276	Membership in a cross product requiring no quantifiers or dummy variables. Provides a slightly shorter version of elxp4 5275 when the double intersection does not create class existence problems (caused by int0 3984). (Contributed by NM, 1-Aug-2004.)
|- ( A e. ( B X. C ) <-> ( A = <. |^| |^| A , U. ran { A } >. /\ ( |^| |^| A e. B /\ U. ran { A } e. C ) ) )
Theorem	cnvresima 5277	An image under the converse of a restriction. (Contributed by Jeff Hankins, 12-Jul-2009.)
|- ( `' ( F |` A ) " B ) = ( ( `' F " B ) i^i A )
Theorem	resdm2 5278	A class restricted to its domain equals its double converse. (Contributed by NM, 8-Apr-2007.)
|- ( A |` dom A ) = `' `' A
Theorem	resdmres 5279	Restriction to the domain of a restriction. (Contributed by NM, 8-Apr-2007.)
|- ( A |` dom ( A |` B ) ) = ( A |` B )
Theorem	imadmres 5280	The image of the domain of a restriction. (Contributed by NM, 8-Apr-2007.)
|- ( A " dom ( A |` B ) ) = ( A " B )
Theorem	mptpreima 5281*	The preimage of a function in maps-to notation. (Contributed by Stefan O'Rear, 25-Jan-2015.)
|- F = ( x e. A |-> B )   =>    |- ( `' F " C ) = { x e. A | B e. C }
Theorem	mptiniseg 5282*	Converse singleton image of a function defined by maps-to. (Contributed by Stefan O'Rear, 25-Jan-2015.)
|- F = ( x e. A |-> B )   =>    |- ( C e. V -> ( `' F " { C } ) = { x e. A | B = C } )
Theorem	dmmpt 5283	The domain of the mapping operation in general. (Contributed by NM, 16-May-1995.) (Revised by Mario Carneiro, 22-Mar-2015.)
|- F = ( x e. A |-> B )   =>    |- dom F = { x e. A | B e. _V }
Theorem	dmmptss 5284*	The domain of a mapping is a subset of its base class. (Contributed by Scott Fenton, 17-Jun-2013.)
|- F = ( x e. A |-> B )   =>    |- dom F C_ A
Theorem	dmmptg 5285*	The domain of the mapping operation is the stated domain, if the function value is always a set. (Contributed by Mario Carneiro, 9-Feb-2013.) (Revised by Mario Carneiro, 14-Sep-2013.)
|- ( A. x e. A B e. V -> dom ( x e. A |-> B ) = A )
Theorem	relco 5286	A composition is a relation. Exercise 24 of [TakeutiZaring] p. 25. (Contributed by NM, 26-Jan-1997.)
|- Rel ( A o. B )
Theorem	dfco2 5287*	Alternate definition of a class composition, using only one bound variable. (Contributed by NM, 19-Dec-2008.)
|- ( A o. B ) = U_ x e. _V ( ( `' B " { x } ) X. ( A " { x } ) )
Theorem	dfco2a 5288*	Generalization of dfco2 5287, where C can have any value between dom A i^i ran B and _V. (Contributed by NM, 21-Dec-2008.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( ( dom A i^i ran B ) C_ C -> ( A o. B ) = U_ x e. C ( ( `' B " { x } ) X. ( A " { x } ) ) )
Theorem	coundi 5289	Class composition distributes over union. (Contributed by NM, 21-Dec-2008.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( A o. ( B u. C ) ) = ( ( A o. B ) u. ( A o. C ) )
Theorem	coundir 5290	Class composition distributes over union. (Contributed by NM, 21-Dec-2008.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( ( A u. B ) o. C ) = ( ( A o. C ) u. ( B o. C ) )
Theorem	cores 5291	Restricted first member of a class composition. (Contributed by NM, 12-Oct-2004.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
|- ( ran B C_ C -> ( ( A |` C ) o. B ) = ( A o. B ) )
Theorem	resco 5292	Associative law for the restriction of a composition. (Contributed by NM, 12-Dec-2006.)
|- ( ( A o. B ) |` C ) = ( A o. ( B |` C ) )
Theorem	imaco 5293	Image of the composition of two classes. (Contributed by Jason Orendorff, 12-Dec-2006.)
|- ( ( A o. B ) " C ) = ( A " ( B " C ) )
Theorem	rnco 5294	The range of the composition of two classes. (Contributed by NM, 12-Dec-2006.)
|- ran ( A o. B ) = ran ( A |` ran B )
Theorem	rnco2 5295	The range of the composition of two classes. (Contributed by NM, 27-Mar-2008.)
|- ran ( A o. B ) = ( A " ran B )
Theorem	dmco 5296	The domain of a composition. Exercise 27 of [Enderton] p. 53. (Contributed by NM, 4-Feb-2004.)
|- dom ( A o. B ) = ( `' B " dom A )
Theorem	coiun 5297*	Composition with an indexed union. (Contributed by NM, 21-Dec-2008.)
|- ( A o. U_ x e. C B ) = U_ x e. C ( A o. B )
Theorem	cocnvcnv1 5298	A composition is not affected by a double converse of its first argument. (Contributed by NM, 8-Oct-2007.)
|- ( `' `' A o. B ) = ( A o. B )
Theorem	cocnvcnv2 5299	A composition is not affected by a double converse of its second argument. (Contributed by NM, 8-Oct-2007.)
|- ( A o. `' `' B ) = ( A o. B )
Theorem	cores2 5300	Absorption of a reverse (preimage) restriction of the second member of a class composition. (Contributed by NM, 11-Dec-2006.)
|- ( dom A C_ C -> ( A o. `' ( `' B |` C ) ) = ( A o. B ) )