Nuprl Lemma : fix_wf1

∀[F:{F:ℕ ⟶ Type| Top ⊆r (F 0)} ]. ∀[G:⋂n:ℕ. ((F n) ⟶ (F (n + 1)))].  (fix(G) ∈ ⋂n:ℕ. (F n))


Proof




Definitions occuring in Statement :  nat: ℕ,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  top: Top,  member: t ∈ T,  set: {x:A| B[x]} ,  apply: f a,  fix: fix(F),  isect: ⋂x:A. B[x],  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  not: ¬A,  all: ∀x:A. B[x],  top: Top,  and: P ∧ Q,  prop: ℙ,  decidable: Dec(P),  or: P ∨ Q,  subtype_rel: A ⊆r B,  le: A ≤ B,  less_than': less_than'(a;b)
Lemmas referenced :  subtype_rel_self,  subtract-add-cancel,  false_wf,  top_wf,  subtype_rel_wf,  le_wf,  int_term_value_add_lemma,  itermAdd_wf,  nat_wf,  int_term_value_subtract_lemma,  int_formula_prop_not_lemma,  itermSubtract_wf,  intformnot_wf,  subtract_wf,  decidable__le,  less_than_wf,  ge_wf,  int_formula_prop_wf,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_and_lemma,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  intformand_wf,  satisfiable-full-omega-tt,  nat_properties
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  isect_memberEquality,  setElimination,  thin,  rename,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  hypothesis,  intWeakElimination,  lambdaFormation,  natural_numberEquality,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  dependent_functionElimination,  voidElimination,  voidEquality,  sqequalRule,  independent_pairFormation,  computeAll,  independent_functionElimination,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  unionElimination,  isectEquality,  functionEquality,  applyEquality,  because_Cache,  dependent_set_memberEquality,  addEquality,  setEquality,  cumulativity,  universeEquality

Latex:
\mforall{}[F:\{F:\mBbbN{}  {}\mrightarrow{}  Type|  Top  \msubseteq{}r  (F  0)\}  ].  \mforall{}[G:\mcap{}n:\mBbbN{}.  ((F  n)  {}\mrightarrow{}  (F  (n  +  1)))].    (fix(G)  \mmember{}  \mcap{}n:\mBbbN{}.  (F  n))



Date html generated: 2016_05_15-PM-04_12_51
Last ObjectModification: 2016_01_16-AM-11_07_00

Theory : general


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