Theorem reseq1 4928

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

Assertion

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

Proof of Theorem reseq1

Step	Hyp	Ref	Expression
1		ineq1 3450	. 2 ⊢ (A = B → (A ∩ (C × V)) = (B ∩ (C × V)))
2		df-res 4788	. 2 ⊢ (A ↾ C) = (A ∩ (C × V))
3		df-res 4788	. 2 ⊢ (B ↾ C) = (B ∩ (C × V))
4	1, 2, 3	3eqtr4g 2410	1 ⊢ (A = B → (A ↾ C) = (B ↾ C))

Syntax hints:   → wi 4   = wceq 1642  Vcvv 2859   ∩ cin 3208   × cxp 4770   ↾ cres 4774

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-v 2861  df-nin 3211  df-compl 3212  df-in 3213  df-res 4788

This theorem is referenced by:  reseq1i  4930  reseq1d  4933