Metamath Proof Explorer


Theorem rsp

Description: Restricted specialization. (Contributed by NM, 17-Oct-1996)

Ref Expression
Assertion rsp
|- ( A. x e. A ph -> ( x e. A -> ph ) )

Proof

Step Hyp Ref Expression
1 df-ral
 |-  ( A. x e. A ph <-> A. x ( x e. A -> ph ) )
2 sp
 |-  ( A. x ( x e. A -> ph ) -> ( x e. A -> ph ) )
3 1 2 sylbi
 |-  ( A. x e. A ph -> ( x e. A -> ph ) )