Nuprl Lemma : uimplies-iff-squash-implies
∀[P,Q:ℙ].  (Q supposing P ⇐⇒ (↓P) ⇒ Q)
Proof
Definitions occuring in Statement : 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
iff: P ⇐⇒ Q, 
squash: ↓T, 
implies: P ⇒ Q
Definitions unfolded in proof : 
squash: ↓T, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
rev_implies: P ⇐ Q
Lemmas referenced : 
isect_wf, 
image-type_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
independent_pairFormation, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
baseClosed, 
hypothesis, 
lambdaEquality, 
functionEquality, 
universeEquality, 
imageElimination, 
rename, 
introduction, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
imageMemberEquality
Latex:
\mforall{}[P,Q:\mBbbP{}].    (Q  supposing  P  \mLeftarrow{}{}\mRightarrow{}  (\mdownarrow{}P)  {}\mRightarrow{}  Q)
Date html generated:
2016_05_13-PM-03_07_33
Last ObjectModification:
2016_01_06-PM-05_28_21
Theory : core_2
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