Nuprl Lemma : polymorphic-constant

∀[T:Type]. ∀f:⋂A:Type. (A ⟶ T). ∃t:T. ∀A:Type. ∀x:A.  ((f x) = t ∈ T) supposing mono(T) ∧ value-type(T)


Proof




Definitions occuring in Statement :  mono: mono(T),  value-type: value-type(T),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  and: P ∧ Q,  apply: f a,  isect: ⋂x:A. B[x],  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  and: P ∧ Q,  mono: mono(T),  all: ∀x:A. B[x],  implies: P ⇒ Q,  prop: ℙ,  value-type: value-type(T),  has-value: (a)↓,  cand: A c∧ B,  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  squash: ↓T,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  is-above_wf,  base_wf,  equal-wf-base,  polymorphic-constant-base,  all_wf,  equal_wf,  mono_wf,  value-type_wf,  squash_wf,  true_wf,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  sqequalRule,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairEquality,  lambdaEquality,  dependent_functionElimination,  hypothesisEquality,  axiomEquality,  hypothesis,  extract_by_obid,  isectElimination,  cumulativity,  isect_memberEquality,  axiomSqleEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  rename,  lambdaFormation,  independent_isectElimination,  independent_pairFormation,  dependent_pairFormation,  universeEquality,  instantiate,  applyEquality,  isectEquality,  functionEquality,  productEquality,  pointwiseFunctionalityForEquality,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_functionElimination

Latex:
\mforall{}[T:Type].  \mforall{}f:\mcap{}A:Type.  (A  {}\mrightarrow{}  T).  \mexists{}t:T.  \mforall{}A:Type.  \mforall{}x:A.    ((f  x)  =  t)  supposing  mono(T)  \mwedge{}  value-type(T)



Date html generated: 2018_05_21-PM-01_11_39
Last ObjectModification: 2018_05_01-PM-04_36_51

Theory : num_thy_1


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