Nuprl Lemma : decidable__squash
∀[p:ℙ]. (Dec(p) ⇒ Dec(↓p))
Proof
Definitions occuring in Statement : 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
squash: ↓T, 
implies: P ⇒ Q
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
prop: ℙ
Lemmas referenced : 
decidable_wf, 
sq_stable_from_decidable, 
squash_elim, 
squash_wf, 
decidable_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
because_Cache, 
productElimination, 
universeEquality
Latex:
\mforall{}[p:\mBbbP{}].  (Dec(p)  {}\mRightarrow{}  Dec(\mdownarrow{}p))
Date html generated:
2016_05_13-PM-03_16_17
Last ObjectModification:
2016_01_06-PM-05_21_19
Theory : core_2
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