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Metamath Proof Explorer


Theorem rspe

Description: Restricted specialization. (Contributed by NM, 12-Oct-1999)

Ref Expression
Assertion rspe x A φ x A φ

Proof

Step Hyp Ref Expression
1 19.8a x A φ x x A φ
2 df-rex x A φ x x A φ
3 1 2 sylibr x A φ x A φ