Nuprl Lemma : p-compose-inject

∀[A,B,C:Type]. ∀[g:A ⟶ (B + Top)]. ∀[f:B ⟶ (C + Top)].
  (p-inject(A;C;f o g)) supposing (p-inject(B;C;f) and p-inject(A;B;g))


Proof




Definitions occuring in Statement :  p-inject: p-inject(A;B;f),  p-compose: f o g,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  top: Top,  function: x:A ⟶ B[x],  union: left + right,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  p-inject: p-inject(A;B;f),  all: ∀x:A. B[x],  implies: P ⇒ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  top: Top,  guard: {T},  and: P ∧ Q
Lemmas referenced :  equal_wf,  do-apply_wf,  p-compose_wf,  assert_wf,  can-apply_wf,  top_wf,  subtype_rel_union,  p-inject_wf,  can-apply-compose,  do-apply-compose
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  lambdaFormation,  hypothesis,  extract_by_obid,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  functionExtensionality,  applyEquality,  independent_isectElimination,  because_Cache,  lambdaEquality,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  dependent_functionElimination,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  unionEquality,  universeEquality,  productElimination,  independent_functionElimination

Latex:
\mforall{}[A,B,C:Type].  \mforall{}[g:A  {}\mrightarrow{}  (B  +  Top)].  \mforall{}[f:B  {}\mrightarrow{}  (C  +  Top)].
    (p-inject(A;C;f  o  g))  supposing  (p-inject(B;C;f)  and  p-inject(A;B;g))



Date html generated: 2018_05_21-PM-06_32_59
Last ObjectModification: 2017_07_26-PM-04_51_58

Theory : general


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