Nuprl Lemma : funinv_wf

[n,m:ℕ]. ∀[f:{f:ℕn ⟶ ℕm| Surj(ℕn;ℕm;f)} ].  (inv(f) ∈ {g:ℕm ⟶ ℕn| Inj(ℕm;ℕn;g) ∧ (∀x:ℕm. ((f (g x)) x ∈ ℤ))} )


Proof




Definitions occuring in Statement :  funinv: inv(f) surject: Surj(A;B;f) inject: Inj(A;B;f) int_seg: {i..j-} nat: uall: [x:A]. B[x] all: x:A. B[x] and: P ∧ Q member: t ∈ T set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] natural_number: $n int: equal: t ∈ T
Definitions unfolded in proof :  funinv: inv(f) so_apply: x[s] so_lambda: λ2x.t[x] uiff: uiff(P;Q) prop: top: Top false: False satisfiable_int_formula: satisfiable_int_formula(fmla) implies:  Q not: ¬A or: P ∨ Q decidable: Dec(P) and: P ∧ Q lelt: i ≤ j < k ge: i ≥  guard: {T} exists: x:A. B[x] uimplies: supposing a nat: int_seg: {i..j-} subtype_rel: A ⊆B all: x:A. B[x] surject: Surj(A;B;f) member: t ∈ T uall: [x:A]. B[x] cand: c∧ B inject: Inj(A;B;f)
Lemmas referenced :  nat_wf surject_wf set_wf exists_wf assert_wf assert_of_eq_int equal_wf int_formula_prop_wf int_term_value_var_lemma int_formula_prop_eq_lemma int_formula_prop_not_lemma int_formula_prop_and_lemma itermVar_wf intformeq_wf intformnot_wf intformand_wf full-omega-unsat decidable__equal_int nat_properties int_seg_properties int_seg_wf eq_int_wf mu-bound-property+ inject_wf all_wf decidable__le intformle_wf itermConstant_wf int_formula_prop_le_lemma int_term_value_constant_lemma decidable__lt intformless_wf int_formula_prop_less_lemma lelt_wf and_wf
Rules used in proof :  functionEquality axiomEquality cumulativity addLevel independent_pairFormation voidEquality voidElimination isect_memberEquality intEquality int_eqEquality independent_functionElimination approximateComputation unionElimination applyLambdaEquality equalitySymmetry equalityTransitivity dependent_pairFormation productElimination independent_isectElimination natural_numberEquality sqequalRule because_Cache applyEquality lambdaEquality isectElimination extract_by_obid hypothesisEquality dependent_functionElimination hypothesis lambdaFormation sqequalHypSubstitution rename thin setElimination cut introduction isect_memberFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution dependent_set_memberEquality productEquality

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



Date html generated: 2019_06_20-PM-01_17_35
Last ObjectModification: 2018_08_25-AM-08_20_11

Theory : int_2


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