Nuprl Lemma : squash_sq_or
∀[a,b:ℙ].  uiff(↓a ↓∨ b;a ↓∨ b)
Proof
Definitions occuring in Statement : 
sq_or: a ↓∨ b, 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
squash: ↓T
Definitions unfolded in proof : 
sq_or: a ↓∨ b, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
squash: ↓T, 
prop: ℙ
Lemmas referenced : 
or_wf, 
squash_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
sqequalHypSubstitution, 
imageElimination, 
hypothesis, 
imageMemberEquality, 
hypothesisEquality, 
thin, 
baseClosed, 
lemma_by_obid, 
isectElimination, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality
Latex:
\mforall{}[a,b:\mBbbP{}].    uiff(\mdownarrow{}a  \mdownarrow{}\mvee{}  b;a  \mdownarrow{}\mvee{}  b)
Date html generated:
2016_05_13-PM-03_13_45
Last ObjectModification:
2016_01_06-PM-05_49_38
Theory : core_2
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