Nuprl Lemma : squash_equal
∀[T:Type]. ∀[x,y:T].  uiff(↓x = y ∈ T;x = y ∈ T)
Proof
Definitions occuring in Statement : 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
squash: ↓T
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
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 : 
equal_wf, 
squash_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
sqequalHypSubstitution, 
imageElimination, 
hypothesis, 
lemma_by_obid, 
isectElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
axiomEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}[x,y:T].    uiff(\mdownarrow{}x  =  y;x  =  y)
Date html generated:
2016_05_13-PM-03_14_04
Last ObjectModification:
2016_01_06-PM-05_49_55
Theory : core_2
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