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