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CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical implication
com4t
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com4r
Metamath Proof Explorer
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Theorem
com4t
Description:
Commutation of antecedents. Rotate twice.
(Contributed by
NM
, 25-Apr-1994)
Ref
Expression
Hypothesis
com4.1
⊢
φ
→
ψ
→
χ
→
θ
→
τ
Assertion
com4t
⊢
χ
→
θ
→
φ
→
ψ
→
τ
Proof
Step
Hyp
Ref
Expression
1
com4.1
⊢
φ
→
ψ
→
χ
→
θ
→
τ
2
1
com4l
⊢
ψ
→
χ
→
θ
→
φ
→
τ
3
2
com4l
⊢
χ
→
θ
→
φ
→
ψ
→
τ