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Theorem imp42 577
Description: An importation inference. (Contributed by NM, 26-Apr-1994.)
Hypothesis
Ref Expression
imp4.1 (φ → (ψ → (χ → (θτ))))
Assertion
Ref Expression
imp42 (((φ (ψ χ)) θ) → τ)

Proof of Theorem imp42
StepHypRef Expression
1 imp4.1 . . 3 (φ → (ψ → (χ → (θτ))))
21imp32 422 . 2 ((φ (ψ χ)) → (θτ))
32imp 418 1 (((φ (ψ χ)) θ) → τ)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  wi 4   wa 358
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This proof depends on definitions:  df-bi 177  df-an 360
This theorem is used by:  imp55  584
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