Metamath Proof Explorer


Theorem reseq1d

Description: Equality deduction for restrictions. (Contributed by NM, 21-Oct-2014)

Ref Expression
Hypothesis reseqd.1 ⊢ φ → A = B
Assertion reseq1d ⊢ φ → A ↾ C = B ↾ C

Proof

Step Hyp Ref Expression
1 reseqd.1 ⊢ φ → A = B
2 reseq1 ⊢ A = B → A ↾ C = B ↾ C
3 1 2 syl ⊢ φ → A ↾ C = B ↾ C