Metamath Proof Explorer

Theorem suceq

Description: Equality of successors. (Contributed by NM, 30-Aug-1993) (Proof shortened by Andrew Salmon, 25-Jul-2011)

Ref Expression
Assertion suceq 
|- ( A = B -> suc A = suc B )

Proof

Step Hyp Ref Expression
1 id 
 |-  ( A = B -> A = B )
2 1 suceqd 
 |-  ( A = B -> suc A = suc B )