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: b 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: b supposing a,  implies: P ⇒ Q,  guard: {T},  strong-subtype: strong-subtype(A;B),  cand: A c∧ B,  deq: EqDecider(T),  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  prop: ℙ,  rev_implies: P ⇐ 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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