P. 23 of Theorem List - Intuitionistic Logic Explorer

Theorem List for Intuitionistic Logic Explorer - 2201-2300   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	eqeq1i 2201	Inference from equality to equivalence of equalities. (Contributed by NM, 5-Aug-1993.)
|- A = B   =>    |- ( A = C <-> B = C )
Theorem	eqeq1d 2202	Deduction from equality to equivalence of equalities. (Contributed by NM, 27-Dec-1993.)
|- ( ph -> A = B )   =>    |- ( ph -> ( A = C <-> B = C ) )
Theorem	eqeq2 2203	Equality implies equivalence of equalities. (Contributed by NM, 5-Aug-1993.)
|- ( A = B -> ( C = A <-> C = B ) )
Theorem	eqeq2i 2204	Inference from equality to equivalence of equalities. (Contributed by NM, 5-Aug-1993.)
|- A = B   =>    |- ( C = A <-> C = B )
Theorem	eqeq2d 2205	Deduction from equality to equivalence of equalities. (Contributed by NM, 27-Dec-1993.)
|- ( ph -> A = B )   =>    |- ( ph -> ( C = A <-> C = B ) )
Theorem	eqeq12 2206	Equality relationship among 4 classes. (Contributed by NM, 3-Aug-1994.)
|- ( ( A = B /\ C = D ) -> ( A = C <-> B = D ) )
Theorem	eqeq12i 2207	A useful inference for substituting definitions into an equality. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- C = D   =>    |- ( A = C <-> B = D )
Theorem	eqeq12d 2208	A useful inference for substituting definitions into an equality. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> ( A = C <-> B = D ) )
Theorem	eqeqan12d 2209	A useful inference for substituting definitions into an equality. (Contributed by NM, 9-Aug-1994.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ps -> C = D )   =>    |- ( ( ph /\ ps ) -> ( A = C <-> B = D ) )
Theorem	eqeqan12rd 2210	A useful inference for substituting definitions into an equality. (Contributed by NM, 9-Aug-1994.)
|- ( ph -> A = B )   &    |- ( ps -> C = D )   =>    |- ( ( ps /\ ph ) -> ( A = C <-> B = D ) )
Theorem	eqtr 2211	Transitive law for class equality. Proposition 4.7(3) of [TakeutiZaring] p. 13. (Contributed by NM, 25-Jan-2004.)
|- ( ( A = B /\ B = C ) -> A = C )
Theorem	eqtr2 2212	A transitive law for class equality. (Contributed by NM, 20-May-2005.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ( A = B /\ A = C ) -> B = C )
Theorem	eqtr3 2213	A transitive law for class equality. (Contributed by NM, 20-May-2005.)
|- ( ( A = C /\ B = C ) -> A = B )
Theorem	eqtri 2214	An equality transitivity inference. (Contributed by NM, 5-Aug-1993.)
|- A = B   &    |- B = C   =>    |- A = C
Theorem	eqtr2i 2215	An equality transitivity inference. (Contributed by NM, 21-Feb-1995.)
|- A = B   &    |- B = C   =>    |- C = A
Theorem	eqtr3i 2216	An equality transitivity inference. (Contributed by NM, 6-May-1994.)
|- A = B   &    |- A = C   =>    |- B = C
Theorem	eqtr4i 2217	An equality transitivity inference. (Contributed by NM, 5-Aug-1993.)
|- A = B   &    |- C = B   =>    |- A = C
Theorem	3eqtri 2218	An inference from three chained equalities. (Contributed by NM, 29-Aug-1993.)
|- A = B   &    |- B = C   &    |- C = D   =>    |- A = D
Theorem	3eqtrri 2219	An inference from three chained equalities. (Contributed by NM, 3-Aug-2006.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- B = C   &    |- C = D   =>    |- D = A
Theorem	3eqtr2i 2220	An inference from three chained equalities. (Contributed by NM, 3-Aug-2006.)
|- A = B   &    |- C = B   &    |- C = D   =>    |- A = D
Theorem	3eqtr2ri 2221	An inference from three chained equalities. (Contributed by NM, 3-Aug-2006.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- C = B   &    |- C = D   =>    |- D = A
Theorem	3eqtr3i 2222	An inference from three chained equalities. (Contributed by NM, 6-May-1994.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- A = C   &    |- B = D   =>    |- C = D
Theorem	3eqtr3ri 2223	An inference from three chained equalities. (Contributed by NM, 15-Aug-2004.)
|- A = B   &    |- A = C   &    |- B = D   =>    |- D = C
Theorem	3eqtr4i 2224	An inference from three chained equalities. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- C = A   &    |- D = B   =>    |- C = D
Theorem	3eqtr4ri 2225	An inference from three chained equalities. (Contributed by NM, 2-Sep-1995.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- C = A   &    |- D = B   =>    |- D = C
Theorem	eqtrd 2226	An equality transitivity deduction. (Contributed by NM, 5-Aug-1993.)
|- ( ph -> A = B )   &    |- ( ph -> B = C )   =>    |- ( ph -> A = C )
Theorem	eqtr2d 2227	An equality transitivity deduction. (Contributed by NM, 18-Oct-1999.)
|- ( ph -> A = B )   &    |- ( ph -> B = C )   =>    |- ( ph -> C = A )
Theorem	eqtr3d 2228	An equality transitivity equality deduction. (Contributed by NM, 18-Jul-1995.)
|- ( ph -> A = B )   &    |- ( ph -> A = C )   =>    |- ( ph -> B = C )
Theorem	eqtr4d 2229	An equality transitivity equality deduction. (Contributed by NM, 18-Jul-1995.)
|- ( ph -> A = B )   &    |- ( ph -> C = B )   =>    |- ( ph -> A = C )
Theorem	3eqtrd 2230	A deduction from three chained equalities. (Contributed by NM, 29-Oct-1995.)
|- ( ph -> A = B )   &    |- ( ph -> B = C )   &    |- ( ph -> C = D )   =>    |- ( ph -> A = D )
Theorem	3eqtrrd 2231	A deduction from three chained equalities. (Contributed by NM, 4-Aug-2006.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ph -> B = C )   &    |- ( ph -> C = D )   =>    |- ( ph -> D = A )
Theorem	3eqtr2d 2232	A deduction from three chained equalities. (Contributed by NM, 4-Aug-2006.)
|- ( ph -> A = B )   &    |- ( ph -> C = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> A = D )
Theorem	3eqtr2rd 2233	A deduction from three chained equalities. (Contributed by NM, 4-Aug-2006.)
|- ( ph -> A = B )   &    |- ( ph -> C = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> D = A )
Theorem	3eqtr3d 2234	A deduction from three chained equalities. (Contributed by NM, 4-Aug-1995.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ph -> A = C )   &    |- ( ph -> B = D )   =>    |- ( ph -> C = D )
Theorem	3eqtr3rd 2235	A deduction from three chained equalities. (Contributed by NM, 14-Jan-2006.)
|- ( ph -> A = B )   &    |- ( ph -> A = C )   &    |- ( ph -> B = D )   =>    |- ( ph -> D = C )
Theorem	3eqtr4d 2236	A deduction from three chained equalities. (Contributed by NM, 4-Aug-1995.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ph -> C = A )   &    |- ( ph -> D = B )   =>    |- ( ph -> C = D )
Theorem	3eqtr4rd 2237	A deduction from three chained equalities. (Contributed by NM, 21-Sep-1995.)
|- ( ph -> A = B )   &    |- ( ph -> C = A )   &    |- ( ph -> D = B )   =>    |- ( ph -> D = C )
Theorem	eqtrid 2238	An equality transitivity deduction. (Contributed by NM, 21-Jun-1993.)
|- A = B   &    |- ( ph -> B = C )   =>    |- ( ph -> A = C )
Theorem	eqtr2id 2239	An equality transitivity deduction. (Contributed by NM, 29-Mar-1998.)
|- A = B   &    |- ( ph -> B = C )   =>    |- ( ph -> C = A )
Theorem	eqtr3id 2240	An equality transitivity deduction. (Contributed by NM, 5-Aug-1993.)
|- B = A   &    |- ( ph -> B = C )   =>    |- ( ph -> A = C )
Theorem	eqtr3di 2241	An equality transitivity deduction. (Contributed by NM, 29-Mar-1998.)
|- ( ph -> A = B )   &    |- A = C   =>    |- ( ph -> B = C )
Theorem	eqtrdi 2242	An equality transitivity deduction. (Contributed by NM, 5-Aug-1993.)
|- ( ph -> A = B )   &    |- B = C   =>    |- ( ph -> A = C )
Theorem	eqtr2di 2243	An equality transitivity deduction. (Contributed by NM, 29-Mar-1998.)
|- ( ph -> A = B )   &    |- B = C   =>    |- ( ph -> C = A )
Theorem	eqtr4di 2244	An equality transitivity deduction. (Contributed by NM, 5-Aug-1993.)
|- ( ph -> A = B )   &    |- C = B   =>    |- ( ph -> A = C )
Theorem	eqtr4id 2245	An equality transitivity deduction. (Contributed by NM, 29-Mar-1998.)
|- A = B   &    |- ( ph -> C = B )   =>    |- ( ph -> A = C )
Theorem	sylan9eq 2246	An equality transitivity deduction. (Contributed by NM, 8-May-1994.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- ( ph -> A = B )   &    |- ( ps -> B = C )   =>    |- ( ( ph /\ ps ) -> A = C )
Theorem	sylan9req 2247	An equality transitivity deduction. (Contributed by NM, 23-Jun-2007.)
|- ( ph -> B = A )   &    |- ( ps -> B = C )   =>    |- ( ( ph /\ ps ) -> A = C )
Theorem	sylan9eqr 2248	An equality transitivity deduction. (Contributed by NM, 8-May-1994.)
|- ( ph -> A = B )   &    |- ( ps -> B = C )   =>    |- ( ( ps /\ ph ) -> A = C )
Theorem	3eqtr3g 2249	A chained equality inference, useful for converting from definitions. (Contributed by NM, 15-Nov-1994.)
|- ( ph -> A = B )   &    |- A = C   &    |- B = D   =>    |- ( ph -> C = D )
Theorem	3eqtr3a 2250	A chained equality inference, useful for converting from definitions. (Contributed by Mario Carneiro, 6-Nov-2015.)
|- A = B   &    |- ( ph -> A = C )   &    |- ( ph -> B = D )   =>    |- ( ph -> C = D )
Theorem	3eqtr4g 2251	A chained equality inference, useful for converting to definitions. (Contributed by NM, 5-Aug-1993.)
|- ( ph -> A = B )   &    |- C = A   &    |- D = B   =>    |- ( ph -> C = D )
Theorem	3eqtr4a 2252	A chained equality inference, useful for converting to definitions. (Contributed by NM, 2-Feb-2007.) (Proof shortened by Andrew Salmon, 25-May-2011.)
|- A = B   &    |- ( ph -> C = A )   &    |- ( ph -> D = B )   =>    |- ( ph -> C = D )
Theorem	eq2tri 2253	A compound transitive inference for class equality. (Contributed by NM, 22-Jan-2004.)
|- ( A = C -> D = F )   &    |- ( B = D -> C = G )   =>    |- ( ( A = C /\ B = F ) <-> ( B = D /\ A = G ) )
Theorem	eleq1w 2254	Weaker version of eleq1 2256 (but more general than elequ1 2168) not depending on ax-ext 2175 nor df-cleq 2186. (Contributed by BJ, 24-Jun-2019.)
|- ( x = y -> ( x e. A <-> y e. A ) )
Theorem	eleq2w 2255	Weaker version of eleq2 2257 (but more general than elequ2 2169) not depending on ax-ext 2175 nor df-cleq 2186. (Contributed by BJ, 29-Sep-2019.)
|- ( x = y -> ( A e. x <-> A e. y ) )
Theorem	eleq1 2256	Equality implies equivalence of membership. (Contributed by NM, 5-Aug-1993.)
|- ( A = B -> ( A e. C <-> B e. C ) )
Theorem	eleq2 2257	Equality implies equivalence of membership. (Contributed by NM, 5-Aug-1993.)
|- ( A = B -> ( C e. A <-> C e. B ) )
Theorem	eleq12 2258	Equality implies equivalence of membership. (Contributed by NM, 31-May-1999.)
|- ( ( A = B /\ C = D ) -> ( A e. C <-> B e. D ) )
Theorem	eleq1i 2259	Inference from equality to equivalence of membership. (Contributed by NM, 5-Aug-1993.)
|- A = B   =>    |- ( A e. C <-> B e. C )
Theorem	eleq2i 2260	Inference from equality to equivalence of membership. (Contributed by NM, 5-Aug-1993.)
|- A = B   =>    |- ( C e. A <-> C e. B )
Theorem	eleq12i 2261	Inference from equality to equivalence of membership. (Contributed by NM, 31-May-1994.)
|- A = B   &    |- C = D   =>    |- ( A e. C <-> B e. D )
Theorem	eleq1d 2262	Deduction from equality to equivalence of membership. (Contributed by NM, 5-Aug-1993.)
|- ( ph -> A = B )   =>    |- ( ph -> ( A e. C <-> B e. C ) )
Theorem	eleq2d 2263	Deduction from equality to equivalence of membership. (Contributed by NM, 27-Dec-1993.)
|- ( ph -> A = B )   =>    |- ( ph -> ( C e. A <-> C e. B ) )
Theorem	eleq12d 2264	Deduction from equality to equivalence of membership. (Contributed by NM, 31-May-1994.)
|- ( ph -> A = B )   &    |- ( ph -> C = D )   =>    |- ( ph -> ( A e. C <-> B e. D ) )
Theorem	eleq1a 2265	A transitive-type law relating membership and equality. (Contributed by NM, 9-Apr-1994.)
|- ( A e. B -> ( C = A -> C e. B ) )
Theorem	eqeltri 2266	Substitution of equal classes into membership relation. (Contributed by NM, 5-Aug-1993.)
|- A = B   &    |- B e. C   =>    |- A e. C
Theorem	eqeltrri 2267	Substitution of equal classes into membership relation. (Contributed by NM, 5-Aug-1993.)
|- A = B   &    |- A e. C   =>    |- B e. C
Theorem	eleqtri 2268	Substitution of equal classes into membership relation. (Contributed by NM, 5-Aug-1993.)
|- A e. B   &    |- B = C   =>    |- A e. C
Theorem	eleqtrri 2269	Substitution of equal classes into membership relation. (Contributed by NM, 5-Aug-1993.)
|- A e. B   &    |- C = B   =>    |- A e. C
Theorem	eqeltrd 2270	Substitution of equal classes into membership relation, deduction form. (Contributed by Raph Levien, 10-Dec-2002.)
|- ( ph -> A = B )   &    |- ( ph -> B e. C )   =>    |- ( ph -> A e. C )
Theorem	eqeltrrd 2271	Deduction that substitutes equal classes into membership. (Contributed by NM, 14-Dec-2004.)
|- ( ph -> A = B )   &    |- ( ph -> A e. C )   =>    |- ( ph -> B e. C )
Theorem	eleqtrd 2272	Deduction that substitutes equal classes into membership. (Contributed by NM, 14-Dec-2004.)
|- ( ph -> A e. B )   &    |- ( ph -> B = C )   =>    |- ( ph -> A e. C )
Theorem	eleqtrrd 2273	Deduction that substitutes equal classes into membership. (Contributed by NM, 14-Dec-2004.)
|- ( ph -> A e. B )   &    |- ( ph -> C = B )   =>    |- ( ph -> A e. C )
Theorem	3eltr3i 2274	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- A e. B   &    |- A = C   &    |- B = D   =>    |- C e. D
Theorem	3eltr4i 2275	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- A e. B   &    |- C = A   &    |- D = B   =>    |- C e. D
Theorem	3eltr3d 2276	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- ( ph -> A e. B )   &    |- ( ph -> A = C )   &    |- ( ph -> B = D )   =>    |- ( ph -> C e. D )
Theorem	3eltr4d 2277	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- ( ph -> A e. B )   &    |- ( ph -> C = A )   &    |- ( ph -> D = B )   =>    |- ( ph -> C e. D )
Theorem	3eltr3g 2278	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- ( ph -> A e. B )   &    |- A = C   &    |- B = D   =>    |- ( ph -> C e. D )
Theorem	3eltr4g 2279	Substitution of equal classes into membership relation. (Contributed by Mario Carneiro, 6-Jan-2017.)
|- ( ph -> A e. B )   &    |- C = A   &    |- D = B   =>    |- ( ph -> C e. D )
Theorem	eqeltrid 2280	B membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- A = B   &    |- ( ph -> B e. C )   =>    |- ( ph -> A e. C )
Theorem	eqeltrrid 2281	B membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- B = A   &    |- ( ph -> B e. C )   =>    |- ( ph -> A e. C )
Theorem	eleqtrid 2282	B membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- A e. B   &    |- ( ph -> B = C )   =>    |- ( ph -> A e. C )
Theorem	eleqtrrid 2283	B membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- A e. B   &    |- ( ph -> C = B )   =>    |- ( ph -> A e. C )
Theorem	eqeltrdi 2284	A membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- ( ph -> A = B )   &    |- B e. C   =>    |- ( ph -> A e. C )
Theorem	eqeltrrdi 2285	A membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- ( ph -> B = A )   &    |- B e. C   =>    |- ( ph -> A e. C )
Theorem	eleqtrdi 2286	A membership and equality inference. (Contributed by NM, 4-Jan-2006.)
|- ( ph -> A e. B )   &    |- B = C   =>    |- ( ph -> A e. C )
Theorem	eleqtrrdi 2287	A membership and equality inference. (Contributed by NM, 24-Apr-2005.)
|- ( ph -> A e. B )   &    |- C = B   =>    |- ( ph -> A e. C )
Theorem	eleq2s 2288	Substitution of equal classes into a membership antecedent. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.)
|- ( A e. B -> ph )   &    |- C = B   =>    |- ( A e. C -> ph )
Theorem	eqneltrd 2289	If a class is not an element of another class, an equal class is also not an element. Deduction form. (Contributed by David Moews, 1-May-2017.)
|- ( ph -> A = B )   &    |- ( ph -> -. B e. C )   =>    |- ( ph -> -. A e. C )
Theorem	eqneltrrd 2290	If a class is not an element of another class, an equal class is also not an element. Deduction form. (Contributed by David Moews, 1-May-2017.)
|- ( ph -> A = B )   &    |- ( ph -> -. A e. C )   =>    |- ( ph -> -. B e. C )
Theorem	neleqtrd 2291	If a class is not an element of another class, it is also not an element of an equal class. Deduction form. (Contributed by David Moews, 1-May-2017.)
|- ( ph -> -. C e. A )   &    |- ( ph -> A = B )   =>    |- ( ph -> -. C e. B )
Theorem	neleqtrrd 2292	If a class is not an element of another class, it is also not an element of an equal class. Deduction form. (Contributed by David Moews, 1-May-2017.)
|- ( ph -> -. C e. B )   &    |- ( ph -> A = B )   =>    |- ( ph -> -. C e. A )
Theorem	cleqh 2293*	Establish equality between classes, using bound-variable hypotheses instead of distinct variable conditions. See also cleqf 2361. (Contributed by NM, 5-Aug-1993.)
|- ( y e. A -> A. x y e. A )   &    |- ( y e. B -> A. x y e. B )   =>    |- ( A = B <-> A. x ( x e. A <-> x e. B ) )
Theorem	nelneq 2294	A way of showing two classes are not equal. (Contributed by NM, 1-Apr-1997.)
|- ( ( A e. C /\ -. B e. C ) -> -. A = B )
Theorem	nelneq2 2295	A way of showing two classes are not equal. (Contributed by NM, 12-Jan-2002.)
|- ( ( A e. B /\ -. A e. C ) -> -. B = C )
Theorem	eqsb1lem 2296*	Lemma for eqsb1 2297. (Contributed by Rodolfo Medina, 28-Apr-2010.) (Proof shortened by Andrew Salmon, 14-Jun-2011.)
|- ( [ y / x ] x = A <-> y = A )
Theorem	eqsb1 2297*	Substitution for the left-hand side in an equality. Class version of equsb3 1967. (Contributed by Rodolfo Medina, 28-Apr-2010.)
|- ( [ y / x ] x = A <-> y = A )
Theorem	clelsb1 2298*	Substitution for the first argument of the membership predicate in an atomic formula (class version of elsb1 2171). (Contributed by Rodolfo Medina, 28-Apr-2010.) (Proof shortened by Andrew Salmon, 14-Jun-2011.)
|- ( [ y / x ] x e. A <-> y e. A )
Theorem	clelsb2 2299*	Substitution for the second argument of the membership predicate in an atomic formula (class version of elsb2 2172). (Contributed by Jim Kingdon, 22-Nov-2018.)
|- ( [ y / x ] A e. x <-> A e. y )
Theorem	hbxfreq 2300	A utility lemma to transfer a bound-variable hypothesis builder into a definition. See hbxfrbi 1483 for equivalence version. (Contributed by NM, 21-Aug-2007.)
|- A = B   &    |- ( y e. B -> A. x y e. B )   =>    |- ( y e. A -> A. x y e. A )