Theorem reseq1 4624

Description: Equality theorem for restrictions. (Contributed by NM, 7-Aug-1994.)

Assertion

Ref	Expression
reseq1	⊢ (𝐴 = 𝐵 → (𝐴 ↾ 𝐶) = (𝐵 ↾ 𝐶))

Proof of Theorem reseq1

Step	Hyp	Ref	Expression
1		ineq1 3160	. 2 ⊢ (𝐴 = 𝐵 → (𝐴 ∩ (𝐶 × V)) = (𝐵 ∩ (𝐶 × V)))
2		df-res 4375	. 2 ⊢ (𝐴 ↾ 𝐶) = (𝐴 ∩ (𝐶 × V))
3		df-res 4375	. 2 ⊢ (𝐵 ↾ 𝐶) = (𝐵 ∩ (𝐶 × V))
4	1, 2, 3	3eqtr4g 2138	1 ⊢ (𝐴 = 𝐵 → (𝐴 ↾ 𝐶) = (𝐵 ↾ 𝐶))

Syntax hints:   → wi 4   = wceq 1284  Vcvv 2601   ∩ cin 2972   × cxp 4361   ↾ cres 4365

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-10 1436  ax-11 1437  ax-i12 1438  ax-bndl 1439  ax-4 1440  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468  ax-ext 2063

This theorem depends on definitions:  df-bi 115  df-tru 1287  df-nf 1390  df-sb 1686  df-clab 2068  df-cleq 2074  df-clel 2077  df-nfc 2208  df-v 2603  df-in 2979  df-res 4375

This theorem is referenced by:  reseq1i  4626  reseq1d  4629  imaeq1  4683  relcoi1  4869  tfr0  5960  tfrlemiex  5968