Nuprl Lemma : coW-equiv-iff

∀[A:𝕌']
  ∀B:A ⟶ Type. ∀w,w':coW(A;a.B[a]).
    (coW-equiv(a.B[a];w;w') ⇐⇒ ∀z:coW(A;a.B[a]). (coWmem(a.B[a];z;w) ⇐⇒ coWmem(a.B[a];z;w')))


Proof




Definitions occuring in Statement :  coWmem: coWmem(a.B[a];z;w),  coW-equiv: coW-equiv(a.B[a];w;w'),  coW: coW(A;a.B[a]),  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  label: ...$L... t,  copath-cons: copath-cons(b;x),  coPathAgree: coPathAgree(a.B[a];n;w;p;q),  copathAgree: copathAgree(a.B[a];w;x;y),  sg-legal2: Legal2(x;y),  top: Top,  less_than': less_than'(a;b),  le: A ≤ B,  ext-eq: A ≡ B,  exists: ∃x:A. B[x],  coW-dom: coW-dom(a.B[a];w),  coW-item: coW-item(w;b),  coWmem: coWmem(a.B[a];z;w),  bfalse: ff,  btrue: tt,  ifthenelse: if b then t else f fi ,  subtract: n - m,  eq_int: (i =z j),  coPath: coPath(a.B[a];w;n),  copath: copath(a.B[a];w),  squash: ↓T,  sq_type: SQType(T),  uimplies: b supposing a,  true: True,  false: False,  not: ¬A,  guard: {T},  cand: A c∧ B,  or: P ∨ Q,  decidable: Dec(P),  nat: ℕ,  subtype_rel: A ⊆r B,  copath-nil: (),  copath-length: copath-length(p),  sg-init: InitialPos(g),  pi2: snd(t),  sg-legal1: Legal1(x;y),  pi1: fst(t),  sg-pos: Pos(g),  coW-game: coW-game(a.B[a];w;w'),  coW-equiv: coW-equiv(a.B[a];w;w'),  rev_implies: P ⇐ Q,  so_apply: x[s],  so_lambda: λ2x.t[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x]
Lemmas referenced :  coW-game-step-isom,  isom-preserves-win2,  sg-normalize_wf,  sg-normalize-win2,  simple-game_wf,  copath-nil_wf,  copath-cons_wf,  top_wf,  sg-legal2_wf,  coPathAgree_wf,  equal-wf-base,  coPathAgree0_lemma,  sg-change-init_wf,  win2_wf,  false_wf,  coW-equiv_weakening,  subtype_rel_weakening,  coW-ext,  coW-item_wf,  le_wf,  set_subtype_base,  pi1_wf,  coPath_wf,  pi2_wf,  iff_weakening_equal,  subtype_rel_self,  true_wf,  squash_wf,  equal_wf,  int_subtype_base,  subtype_base_sq,  copath_wf,  equal-wf-T-base,  nat_wf,  copath-length_wf,  decidable__int_equal,  sg-init_wf,  sg-legal1_wf,  sg-pos_wf,  set_wf,  coW-game_wf,  win2-iff,  coW-equiv_inversion,  coW-equiv-implies,  coWmem_wf,  iff_wf,  coW_wf,  all_wf,  coW-equiv_wf
Rules used in proof :  voidEquality,  isect_memberEquality,  independent_pairEquality,  dependent_set_memberEquality,  dependent_pairEquality,  dependent_pairFormation,  hypothesis_subsumption,  applyLambdaEquality,  imageMemberEquality,  imageElimination,  promote_hyp,  independent_isectElimination,  equalityTransitivity,  functionExtensionality,  levelHypothesis,  equalityUniverse,  voidElimination,  inrFormation,  baseClosed,  intEquality,  productEquality,  equalitySymmetry,  inlFormation,  unionElimination,  natural_numberEquality,  rename,  setElimination,  productElimination,  independent_functionElimination,  dependent_functionElimination,  universeEquality,  functionEquality,  because_Cache,  cumulativity,  instantiate,  hypothesis,  applyEquality,  lambdaEquality,  sqequalRule,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  independent_pairFormation,  lambdaFormation,  isect_memberFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}[A:\mBbbU{}']
    \mforall{}B:A  {}\mrightarrow{}  Type.  \mforall{}w,w':coW(A;a.B[a]).
        (coW-equiv(a.B[a];w;w')  \mLeftarrow{}{}\mRightarrow{}  \mforall{}z:coW(A;a.B[a]).  (coWmem(a.B[a];z;w)  \mLeftarrow{}{}\mRightarrow{}  coWmem(a.B[a];z;w')))



Date html generated: 2018_07_25-PM-01_48_57
Last ObjectModification: 2018_07_11-PM-00_21_34

Theory : co-recursion


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