Nuprl Lemma : strong-subtype-deq

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


Proof




Definitions occuring in Statement :  deq: EqDecider(T) strong-subtype: strong-subtype(A;B) uimplies: supposing a uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a implies:  Q guard: {T} strong-subtype: strong-subtype(A;B) cand: c∧ B deq: EqDecider(T) subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q prop: rev_implies:  Q
Lemmas referenced :  strong-subtype-implies subtype_rel_dep_function bool_wf subtype_rel_self equal_wf assert_wf all_wf iff_wf strong-subtype_wf deq_wf equal_functionality_wrt_subtype_rel2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality independent_functionElimination hypothesis productElimination setElimination rename dependent_set_memberEquality applyEquality sqequalRule lambdaEquality functionEquality independent_isectElimination lambdaFormation because_Cache independent_pairFormation axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality universeEquality dependent_functionElimination

Latex:
\mforall{}[A,B:Type].  \mforall{}[d:EqDecider(B)].    d  \mmember{}  EqDecider(A)  supposing  strong-subtype(A;B)



Date html generated: 2016_05_14-AM-06_06_49
Last ObjectModification: 2015_12_26-AM-11_46_54

Theory : equality!deciders


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