Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
anabsi8
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anabss7
Metamath Proof Explorer
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Theorem
anabsi8
Description:
Absorption of antecedent into conjunction.
(Contributed by
NM
, 26-Sep-1999)
Ref
Expression
Hypothesis
anabsi8.1
⊢
ψ
→
ψ
∧
φ
→
χ
Assertion
anabsi8
⊢
φ
∧
ψ
→
χ
Proof
Step
Hyp
Ref
Expression
1
anabsi8.1
⊢
ψ
→
ψ
∧
φ
→
χ
2
1
anabsi5
⊢
ψ
∧
φ
→
χ
3
2
ancoms
⊢
φ
∧
ψ
→
χ