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CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical disjunction
pm2.07
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Metamath Proof Explorer
Ascii
Structured
Theorem
pm2.07
Description:
Theorem *2.07 of
WhiteheadRussell
p. 101.
(Contributed by
NM
, 3-Jan-2005)
Ref
Expression
Assertion
pm2.07
⊢
(
𝜑
→ (
𝜑
∨
𝜑
) )
Proof
Step
Hyp
Ref
Expression
1
olc
⊢
(
𝜑
→ (
𝜑
∨
𝜑
) )