Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical disjunction
pm5.11
Next ⟩
pm5.12
Metamath Proof Explorer
Ascii
Structured
Theorem
pm5.11
Description:
Theorem *5.11 of
WhiteheadRussell
p. 123.
(Contributed by
NM
, 3-Jan-2005)
Ref
Expression
Assertion
pm5.11
⊢
( (
𝜑
→
𝜓
) ∨ ( ¬
𝜑
→
𝜓
) )
Proof
Step
Hyp
Ref
Expression
1
pm5.11g
⊢
( (
𝜑
→
𝜓
) ∨ ( ¬
𝜑
→
𝜓
) )