Nuprl Lemma : or_comm
∀[A,B:ℙ].  (A ∨ B 
⇐⇒ B ∨ A)
Proof
Definitions occuring in Statement : 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
guard: {T}
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
or_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
independent_pairFormation, 
lambdaFormation, 
sqequalHypSubstitution, 
unionElimination, 
thin, 
sqequalRule, 
cut, 
hypothesis, 
inrFormation, 
hypothesisEquality, 
inlFormation, 
introduction, 
extract_by_obid, 
isectElimination, 
because_Cache, 
Error :inhabitedIsType, 
Error :universeIsType, 
universeEquality
Latex:
\mforall{}[A,B:\mBbbP{}].    (A  \mvee{}  B  \mLeftarrow{}{}\mRightarrow{}  B  \mvee{}  A)
Date html generated:
2019_06_20-AM-11_16_01
Last ObjectModification:
2018_09_26-AM-10_23_57
Theory : core_2
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