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Theorem prlem1 576
Description: A specialized lemma for set theory (axiom of pairing).
Hypotheses
Ref Expression
prlem1.1 (φ → (ηχ))
prlem1.2 (ψ → ¬ θ)
Assertion
Ref Expression
prlem1 (φ → (ψ → (((ψχ) ∨ (θτ)) → η)))

Proof of Theorem prlem1
StepHypRef Expression
1 prlem1.1 . . . . . 6 (φ → (ηχ))
21biimprcd 138 . . . . 5 (χ → (φη))
32adantl 305 . . . 4 ((ψχ) → (φη))
43a1dd 42 . . 3 ((ψχ) → (φ → (ψη)))
5 pm2.24 72 . . . . . 6 (θ → (¬ θη))
6 prlem1.2 . . . . . 6 (ψ → ¬ θ)
75, 6syl5 22 . . . . 5 (θ → (ψη))
87adantr 306 . . . 4 ((θτ) → (ψη))
98a1d 14 . . 3 ((θτ) → (φ → (ψη)))
104, 9jaoi 275 . 2 (((ψχ) ∨ (θτ)) → (φ → (ψη)))
1110com3l 34 1 (φ → (ψ → (((ψχ) ∨ (θτ)) → η)))
Colors of variables: wff set class
Syntax hints:  ¬ wn 1   → wi 2   ↔ wb 127   ∨ wo 195   ∧ wa 196
This theorem is referenced by:  zfpair 1891
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198
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