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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