Metamath Proof Explorer


Theorem nfra2

Description: Similar to Lemma 24 of Monk2 p. 114, except the quantification of the antecedent is restricted. Derived automatically from hbra2VD . Usage of this theorem is discouraged because it depends on ax-13 . Use the weaker nfra2w when possible. (Contributed by Alan Sare, 31-Dec-2011) (New usage is discouraged.)

Ref Expression
Assertion nfra2 y x A y B φ

Proof

Step Hyp Ref Expression
1 nfcv _ y A
2 nfra1 y y B φ
3 1 2 nfral y x A y B φ