Nuprl Lemma : rel-preserving-composes

[T1,T2,T3:Type]. ∀[R1:T1 ⟶ T1 ⟶ Type]. ∀[R2:T2 ⟶ T2 ⟶ Type]. ∀[R3:T3 ⟶ T3 ⟶ ℙ].
  ∀f:T2 ⟶ T1. ∀g:T3 ⟶ T2.
    x.f[x]:T2->T1 takes R2 into R1*)  λx.g[x]:T3->T2 takes R3 into R2*)  λx.f[g[x]]:T3->T1 takes R3 into R1*))


Proof




Definitions occuring in Statement :  rel-preserving: λx.f[x]:T2->T1 takes R2 into R1*) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] implies:  Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] implies:  Q member: t ∈ T so_lambda: λ2x.t[x] so_apply: x[s] prop: rel-preserving: λx.f[x]:T2->T1 takes R2 into R1*) infix_ap: y subtype_rel: A ⊆B guard: {T}
Lemmas referenced :  rel-preserving-star rel-preserving_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality dependent_functionElimination sqequalRule lambdaEquality applyEquality independent_functionElimination hypothesis addLevel levelHypothesis functionEquality cumulativity universeEquality because_Cache

Latex:
\mforall{}[T1,T2,T3:Type].  \mforall{}[R1:T1  {}\mrightarrow{}  T1  {}\mrightarrow{}  Type].  \mforall{}[R2:T2  {}\mrightarrow{}  T2  {}\mrightarrow{}  Type].  \mforall{}[R3:T3  {}\mrightarrow{}  T3  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}f:T2  {}\mrightarrow{}  T1.  \mforall{}g:T3  {}\mrightarrow{}  T2.
        (\mlambda{}x.f[x]:T2->T1  takes  R2  into  R1*)
        {}\mRightarrow{}  \mlambda{}x.g[x]:T3->T2  takes  R3  into  R2*)
        {}\mRightarrow{}  \mlambda{}x.f[g[x]]:T3->T1  takes  R3  into  R1*))



Date html generated: 2016_05_15-PM-05_40_59
Last ObjectModification: 2015_12_27-PM-00_32_38

Theory : general


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