Nuprl Lemma : squash_elim
∀[P:ℙ]. (SqStable(P) ⇒ (↓P ⇐⇒ P))
Proof
Definitions occuring in Statement : 
sq_stable: SqStable(P), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
iff: P ⇐⇒ Q, 
squash: ↓T, 
implies: P ⇒ Q
Definitions unfolded in proof : 
sq_stable: SqStable(P), 
uall: ∀[x:A]. B[x], 
implies: P ⇒ Q, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
member: t ∈ T, 
prop: ℙ, 
rev_implies: P ⇐ Q, 
squash: ↓T
Lemmas referenced : 
squash_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
Error :isect_memberFormation_alt, 
lambdaFormation, 
independent_pairFormation, 
sqequalHypSubstitution, 
independent_functionElimination, 
thin, 
hypothesis, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
imageMemberEquality, 
baseClosed, 
functionEquality, 
Error :universeIsType, 
universeEquality
Latex:
\mforall{}[P:\mBbbP{}].  (SqStable(P)  {}\mRightarrow{}  (\mdownarrow{}P  \mLeftarrow{}{}\mRightarrow{}  P))
Date html generated:
2019_06_20-AM-11_15_47
Last ObjectModification:
2018_09_26-AM-10_23_47
Theory : core_2
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