Metamath Proof Explorer


Theorem modfsummodslem1

Description: Lemma 1 for modfsummods . (Contributed by Alexander van der Vekens, 1-Sep-2018)

Ref Expression
Assertion modfsummodslem1 k A z B z / k B

Proof

Step Hyp Ref Expression
1 vsnid z z
2 elun2 z z z A z
3 1 2 ax-mp z A z
4 rspcsbela z A z k A z B z / k B
5 3 4 mpan k A z B z / k B