Metamath Proof Explorer


Theorem reseq1d

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

Ref Expression
Hypothesis reseqd.1 φA=B
Assertion reseq1d φAC=BC

Proof

Step Hyp Ref Expression
1 reseqd.1 φA=B
2 reseq1 A=BAC=BC
3 1 2 syl φAC=BC