Nuprl Lemma : compact-union

∀[T,S:Type].  (compact-type(T) ⇒ compact-type(S) ⇒ compact-type(T + S))


Proof




Definitions occuring in Statement :  compact-type: compact-type(T),  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  union: left + right,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  compact-type: compact-type(T),  all: ∀x:A. B[x],  member: t ∈ T,  prop: ℙ,  or: P ∨ Q,  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  bool_wf,  compact-type_wf,  equal-wf-T-base,  all_wf,  equal_wf,  squash_wf,  true_wf,  btrue_wf,  iff_weakening_equal,  exists_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  functionEquality,  unionEquality,  cumulativity,  hypothesisEquality,  cut,  introduction,  extract_by_obid,  hypothesis,  isectElimination,  thin,  universeEquality,  dependent_functionElimination,  lambdaEquality,  applyEquality,  functionExtensionality,  inlEquality,  sqequalRule,  unionElimination,  productElimination,  inlFormation,  dependent_pairFormation,  baseClosed,  inrEquality,  inrFormation,  imageElimination,  equalityTransitivity,  equalitySymmetry,  natural_numberEquality,  imageMemberEquality,  independent_isectElimination,  independent_functionElimination,  because_Cache

Latex:
\mforall{}[T,S:Type].    (compact-type(T)  {}\mRightarrow{}  compact-type(S)  {}\mRightarrow{}  compact-type(T  +  S))



Date html generated: 2017_10_01-AM-08_29_00
Last ObjectModification: 2017_07_26-PM-04_23_46

Theory : basic


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