Metamath Proof Explorer

Theorem s1eqd

Description: Equality theorem for a singleton word. (Contributed by Mario Carneiro, 26-Feb-2016)

Ref Expression
Hypothesis s1eqd.1 
|- ( ph -> A = B )
Assertion s1eqd 
|- ( ph -> <" A "> = <" B "> )

Proof

Step Hyp Ref Expression
1 s1eqd.1 
 |-  ( ph -> A = B )
2 s1eq 
 |-  ( A = B -> <" A "> = <" B "> )
3 1 2 syl 
 |-  ( ph -> <" A "> = <" B "> )