Metamath Proof Explorer


Theorem suceqd

Description: Deduction associated with suceq . (Contributed by Rohan Ridenour, 8-Aug-2023)

Ref Expression
Hypothesis suceqd.1
|- ( ph -> A = B )
Assertion suceqd
|- ( ph -> suc A = suc B )

Proof

Step Hyp Ref Expression
1 suceqd.1
 |-  ( ph -> A = B )
2 1 sneqd
 |-  ( ph -> { A } = { B } )
3 1 2 uneq12d
 |-  ( ph -> ( A u. { A } ) = ( B u. { B } ) )
4 df-suc
 |-  suc A = ( A u. { A } )
5 df-suc
 |-  suc B = ( B u. { B } )
6 3 4 5 3eqtr4g
 |-  ( ph -> suc A = suc B )