Nuprl Lemma : funinv-funinv

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


Proof




Definitions occuring in Statement :  funinv: inv(f) inject: Inj(A;B;f) int_seg: {i..j-} nat: uall: [x:A]. B[x] set: {x:A| B[x]}  function: x:A ⟶ B[x] natural_number: $n equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T squash: T nat: prop: so_lambda: λ2x.t[x] so_apply: x[s] inject: Inj(A;B;f) all: x:A. B[x] subtype_rel: A ⊆B implies:  Q and: P ∧ Q guard: {T} int_seg: {i..j-} lelt: i ≤ j < k ge: i ≥  decidable: Dec(P) or: P ∨ Q uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A top: Top
Lemmas referenced :  int_formula_prop_less_lemma intformless_wf decidable__lt int_term_value_constant_lemma int_formula_prop_le_lemma itermConstant_wf intformle_wf decidable__le 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 satisfiable-full-omega-tt decidable__equal_int nat_properties lelt_wf int_seg_properties funinv-property nat_wf set_wf inject_wf int_seg_wf funinv_wf2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis applyEquality lambdaEquality setElimination rename sqequalRule imageMemberEquality baseClosed setEquality functionEquality natural_numberEquality imageElimination dependent_set_memberEquality functionExtensionality isect_memberEquality axiomEquality because_Cache dependent_functionElimination independent_functionElimination equalityTransitivity equalitySymmetry productElimination intEquality unionElimination independent_isectElimination dependent_pairFormation int_eqEquality voidElimination voidEquality independent_pairFormation computeAll

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



Date html generated: 2016_05_14-AM-07_30_51
Last ObjectModification: 2016_01_14-PM-10_01_36

Theory : int_2


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