Nuprl Lemma : inject-subtype

∀[C,A:Type].  ∀[B:Type]. ∀[f:A ⟶ B].  Inj(C;B;f) supposing Inj(A;B;f) supposing strong-subtype(C;A)


Proof




Definitions occuring in Statement :  strong-subtype: strong-subtype(A;B),  inject: Inj(A;B;f),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  inject: Inj(A;B;f),  all: ∀x:A. B[x],  subtype_rel: A ⊆r B,  strong-subtype: strong-subtype(A;B),  cand: A c∧ B,  implies: P ⇒ Q,  label: ...$L... t,  guard: {T},  prop: ℙ
Lemmas referenced :  strong-subtype-eq1,  inject_wf,  strong-subtype_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  sqequalHypSubstitution,  lambdaFormation_alt,  hypothesis,  dependent_functionElimination,  thin,  hypothesisEquality,  applyEquality,  productElimination,  sqequalRule,  independent_functionElimination,  extract_by_obid,  isectElimination,  because_Cache,  independent_isectElimination,  equalityIstype,  universeIsType,  lambdaEquality_alt,  axiomEquality,  functionIsTypeImplies,  inhabitedIsType,  isect_memberEquality_alt,  isectIsTypeImplies,  functionIsType,  instantiate,  universeEquality

Latex:
\mforall{}[C,A:Type].    \mforall{}[B:Type].  \mforall{}[f:A  {}\mrightarrow{}  B].    Inj(C;B;f)  supposing  Inj(A;B;f)  supposing  strong-subtype(C;A)



Date html generated: 2020_05_19-PM-09_36_21
Last ObjectModification: 2020_01_25-PM-08_00_58

Theory : subtype_1


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