Nuprl Lemma : funinv-property

∀[n:ℕ]. ∀[f:{f:ℕn ⟶ ℕn| Inj(ℕn;ℕn;f)} ]. ∀[x:ℕn].  (((f (inv(f) x)) = x ∈ ℤ) ∧ ((inv(f) (f x)) = x ∈ ℕn))


Proof




Definitions occuring in Statement :  funinv: inv(f),  inject: Inj(A;B;f),  int_seg: {i..j-},  nat: ℕ,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  and: P ∧ Q,  nat: ℕ,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  int_seg: {i..j-},  all: ∀x:A. B[x],  uimplies: b supposing a,  squash: ↓T,  cand: A c∧ B,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  inject: Inj(A;B;f),  lelt: i ≤ j < k,  ge: i ≥ j ,  le: A ≤ B,  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  false: False,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  sq_stable: SqStable(P)
Lemmas referenced :  funinv_wf2,  int_seg_wf,  set_wf,  inject_wf,  nat_wf,  equal_wf,  squash_wf,  injection-is-surjection,  surject_wf,  true_wf,  iff_weakening_equal,  int_seg_properties,  nat_properties,  decidable__le,  lelt_wf,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformnot_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_not_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  sq_stable__and,  sq_stable__equal,  funinv_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  setElimination,  rename,  sqequalRule,  productElimination,  independent_pairEquality,  axiomEquality,  hypothesis,  natural_numberEquality,  isect_memberEquality,  because_Cache,  functionEquality,  lambdaEquality,  functionExtensionality,  applyEquality,  intEquality,  dependent_set_memberEquality,  setEquality,  dependent_functionElimination,  independent_isectElimination,  applyLambdaEquality,  imageMemberEquality,  baseClosed,  imageElimination,  equalityTransitivity,  equalitySymmetry,  universeEquality,  independent_functionElimination,  independent_pairFormation,  unionElimination,  voidElimination,  dependent_pairFormation,  int_eqEquality,  voidEquality,  computeAll,  lambdaFormation

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[f:\{f:\mBbbN{}n  {}\mrightarrow{}  \mBbbN{}n|  Inj(\mBbbN{}n;\mBbbN{}n;f)\}  ].  \mforall{}[x:\mBbbN{}n].    (((f  (inv(f)  x))  =  x)  \mwedge{}  ((inv(f)  (f  x))  =  x))



Date html generated: 2017_04_14-AM-09_19_17
Last ObjectModification: 2017_02_27-PM-03_55_22

Theory : int_2


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