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Theorem 2a1i 24
Description: Add two antecedents to a wff. (Contributed by Jeff Hankins, 4-Aug-2009.) (Proof shortened by Wolf Lammen, 23-Jul-2013.)
Hypothesis
Ref Expression
2a1i.1 χ
Assertion
Ref Expression
2a1i (φ → (ψχ))

Proof of Theorem 2a1i
StepHypRef Expression
1 2a1i.1 . . 3 χ
21a1i 10 . 2 (φχ)
32a1d 22 1 (φ → (ψχ))
Colors of variables: wff setvar class
Syntax hints:  wi 4
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7
This theorem is referenced by:  ax12dgen3  1727  equvini  1987  ax11f  2192
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