Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
True and false constants
The false constant
bifal
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falim
Metamath Proof Explorer
Ascii
Structured
Theorem
bifal
Description:
A contradiction is equivalent to falsehood.
(Contributed by
Mario Carneiro
, 9-May-2015)
Ref
Expression
Hypothesis
bifal.1
⊢
¬
𝜑
Assertion
bifal
⊢
(
𝜑
↔ ⊥ )
Proof
Step
Hyp
Ref
Expression
1
bifal.1
⊢
¬
𝜑
2
fal
⊢
¬ ⊥
3
1
2
2false
⊢
(
𝜑
↔ ⊥ )