Theorem ineq2 3322

Description: Equality theorem for intersection of two classes. (Contributed by NM, 26-Dec-1993.)

Assertion

Ref	Expression
ineq2	⊢ (𝐴 = 𝐵 → (𝐶 ∩ 𝐴) = (𝐶 ∩ 𝐵))

Proof of Theorem ineq2

Step	Hyp	Ref	Expression
1		ineq1 3321	. 2 ⊢ (𝐴 = 𝐵 → (𝐴 ∩ 𝐶) = (𝐵 ∩ 𝐶))
2		incom 3319	. 2 ⊢ (𝐶 ∩ 𝐴) = (𝐴 ∩ 𝐶)
3		incom 3319	. 2 ⊢ (𝐶 ∩ 𝐵) = (𝐵 ∩ 𝐶)
4	1, 2, 3	3eqtr4g 2228	1 ⊢ (𝐴 = 𝐵 → (𝐶 ∩ 𝐴) = (𝐶 ∩ 𝐵))

Syntax hints:   → wi 4   = wceq 1348   ∩ cin 3120

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-tru 1351  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-v 2732  df-in 3127

This theorem is referenced by:  ineq12  3323  ineq2i  3325  ineq2d  3328  uneqin  3378  intprg  3864  fiintim  6906  uzin2  10951  inopn  12795  basis1  12839  basis2  12840  baspartn  12842  metreslem  13174  qtopbasss  13315