Nuprl Lemma : inl-one-one'

∀[A,B:Type]. ∀[x,y:A].  x = y ∈ A supposing (inl x) = (inl y) ∈ (A + B)


Proof




Definitions occuring in Statement :  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  inl: inl x,  union: left + right,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a
Lemmas referenced :  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  sqequalHypSubstitution,  sqequalRule,  applyLambdaEquality,  unionElimination,  thin,  hypothesisEquality,  hypothesis,  equalityIstype,  unionIsType,  universeIsType,  inlEquality_alt,  isect_memberEquality_alt,  isectElimination,  axiomEquality,  isectIsTypeImplies,  inhabitedIsType,  instantiate,  extract_by_obid,  universeEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[x,y:A].    x  =  y  supposing  (inl  x)  =  (inl  y)



Date html generated: 2020_05_19-PM-09_35_13
Last ObjectModification: 2019_12_05-PM-02_55_57

Theory : union


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