Nuprl Lemma : strong-subtype-equal
∀[A,B:Type].  strong-subtype(A;B) supposing A = B ∈ Type
Proof
Definitions occuring in Statement : 
strong-subtype: strong-subtype(A;B)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
equal_wf, 
strong-subtype_witness, 
strong-subtype-self, 
iff_weakening_equal, 
true_wf, 
squash_wf, 
strong-subtype_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeEquality, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
because_Cache, 
instantiate, 
isect_memberEquality
Latex:
\mforall{}[A,B:Type].    strong-subtype(A;B)  supposing  A  =  B
Date html generated:
2016_05_13-PM-04_11_00
Last ObjectModification:
2016_01_14-PM-07_29_46
Theory : subtype_1
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