Nuprl Lemma : p-fun-exp-one

∀[A:Type]. ∀[f:A ⟶ (A + Top)].  (f^1 = f ∈ (A ⟶ (A + Top)))


Proof




Definitions occuring in Statement :  p-fun-exp: f^n,  uall: ∀[x:A]. B[x],  top: Top,  function: x:A ⟶ B[x],  union: left + right,  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  p-fun-exp: f^n,  all: ∀x:A. B[x],  member: t ∈ T,  top: Top,  uall: ∀[x:A]. B[x],  squash: ↓T,  prop: ℙ,  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q
Lemmas referenced :  primrec1_lemma,  equal_wf,  squash_wf,  true_wf,  top_wf,  p-compose-id,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  isect_memberFormation,  applyEquality,  lambdaEquality,  imageElimination,  isectElimination,  hypothesisEquality,  equalityTransitivity,  equalitySymmetry,  universeEquality,  functionEquality,  cumulativity,  unionEquality,  because_Cache,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_isectElimination,  productElimination,  independent_functionElimination,  axiomEquality

Latex:
\mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  (A  +  Top)].    (f\^{}1  =  f)



Date html generated: 2017_10_01-AM-09_14_25
Last ObjectModification: 2017_07_26-PM-04_49_32

Theory : general


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