Nuprl Lemma : strong-subtype-deq-subtype

[A,B:Type].  EqDecider(B) ⊆EqDecider(A) supposing strong-subtype(A;B)


Proof




Definitions occuring in Statement :  deq: EqDecider(T) strong-subtype: strong-subtype(A;B) uimplies: supposing a subtype_rel: A ⊆B uall: [x:A]. B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a subtype_rel: A ⊆B prop:
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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