Nuprl Lemma : strong-subtype-deq-subtype
∀[A,B:Type].  EqDecider(B) ⊆r EqDecider(A) supposing strong-subtype(A;B)
Proof
Definitions occuring in Statement : 
deq: EqDecider(T)
, 
strong-subtype: strong-subtype(A;B)
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
Lemmas referenced : 
strong-subtype-deq, 
deq_wf, 
strong-subtype_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaEquality, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
independent_isectElimination, 
hypothesis, 
sqequalRule, 
axiomEquality, 
isect_memberEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality
Latex:
\mforall{}[A,B:Type].    EqDecider(B)  \msubseteq{}r  EqDecider(A)  supposing  strong-subtype(A;B)
Date html generated:
2016_05_14-AM-06_06_50
Last ObjectModification:
2015_12_26-AM-11_46_34
Theory : equality!deciders
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