Nuprl Lemma : squash-per-class
∀[T:Type]. ∀[a:T].  (↓per-class(T;a))
Proof
Definitions occuring in Statement : 
per-class: per-class(T;a)
, 
uall: ∀[x:A]. B[x]
, 
squash: ↓T
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
squash: ↓T
, 
per-class: per-class(T;a)
, 
prop: ℙ
, 
uimplies: b supposing a
, 
guard: {T}
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
true: True
Lemmas referenced : 
b-union_wf, 
equal_functionality_wrt_subtype_rel2, 
base_wf, 
subtype_rel_b-union-right, 
per-class_wf, 
true_wf, 
squash_wf, 
equal-wf-base-T
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
hypothesis, 
sqequalHypSubstitution, 
imageElimination, 
sqequalRule, 
imageMemberEquality, 
hypothesisEquality, 
thin, 
baseClosed, 
isect_memberEquality, 
isectElimination, 
because_Cache, 
universeEquality, 
pointwiseFunctionality, 
dependent_set_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
lemma_by_obid, 
applyEquality, 
lambdaEquality, 
independent_isectElimination, 
independent_functionElimination, 
natural_numberEquality
Latex:
\mforall{}[T:Type].  \mforall{}[a:T].    (\mdownarrow{}per-class(T;a))
Date html generated:
2016_05_13-PM-04_12_34
Last ObjectModification:
2016_01_14-PM-07_29_30
Theory : subtype_1
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