Nuprl Lemma : WtoSet-order-preserving

∀[A:Type]. ∀[B:A ⟶ Type].
  ∀x,y:W(A;a.B[a]). ∀b:𝔹.  ((x Wcmp(A;a.B[a];b) y) ⇒ (WtoSet(a.B[a];x) Wcmp(Type;a.a;b) WtoSet(a.B[a];y)))


Proof




Definitions occuring in Statement :  WtoSet: WtoSet(a.B[a];x),  Wcmp: Wcmp(A;a.B[a];leq),  W: W(A;a.B[a]),  bool: 𝔹,  uall: ∀[x:A]. B[x],  infix_ap: x f y,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  implies: P ⇒ Q,  prop: ℙ,  infix_ap: x f y,  subtype_rel: A ⊆r B,  Set: Set{i:l},  all: ∀x:A. B[x],  WtoSet: WtoSet(a.B[a];x),  Wsup: Wsup(a;b),  Wcmp: Wcmp(A;a.B[a];leq),  mk-set: f"(T),  bool: 𝔹,  ifthenelse: if b then t else f fi ,  exists: ∃x:A. B[x]
Lemmas referenced :  W-induction,  all_wf,  W_wf,  bool_wf,  Wcmp_wf,  WtoSet_wf,  subtype_rel_self,  Wsup_wf,  btrue_wf,  mk-set_wf,  bfalse_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  sqequalRule,  lambdaEquality,  applyEquality,  hypothesis,  functionEquality,  universeEquality,  because_Cache,  independent_functionElimination,  lambdaFormation,  unionElimination,  dependent_functionElimination,  productElimination,  dependent_pairFormation

Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].
    \mforall{}x,y:W(A;a.B[a]).  \mforall{}b:\mBbbB{}.
        ((x  Wcmp(A;a.B[a];b)  y)  {}\mRightarrow{}  (WtoSet(a.B[a];x)  Wcmp(Type;a.a;b)  WtoSet(a.B[a];y)))



Date html generated: 2018_05_22-PM-09_52_07
Last ObjectModification: 2018_05_16-PM-01_31_46

Theory : constructive!set!theory


Home Index