Metamath Proof Explorer


Theorem r19.26

Description: Restricted quantifier version of 19.26 . (Contributed by NM, 28-Jan-1997) (Proof shortened by Andrew Salmon, 30-May-2011)

Ref Expression
Assertion r19.26 x A φ ψ x A φ x A ψ

Proof

Step Hyp Ref Expression
1 simpl φ ψ φ
2 1 ralimi x A φ ψ x A φ
3 simpr φ ψ ψ
4 3 ralimi x A φ ψ x A ψ
5 2 4 jca x A φ ψ x A φ x A ψ
6 pm3.2 φ ψ φ ψ
7 6 ral2imi x A φ x A ψ x A φ ψ
8 7 imp x A φ x A ψ x A φ ψ
9 5 8 impbii x A φ ψ x A φ x A ψ