Nuprl Lemma : funinv-unique

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


Proof




Definitions occuring in Statement :  funinv: inv(f) inject: Inj(A;B;f) compose: g int_seg: {i..j-} nat: uimplies: supposing a uall: [x:A]. B[x] set: {x:A| B[x]}  lambda: λx.A[x] function: x:A ⟶ B[x] natural_number: $n equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a nat: prop: squash: T 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 compose: g and: P ∧ Q guard: {T} int_seg: {i..j-} lelt: i ≤ j < k ge: i ≥  decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A top: Top
Lemmas referenced :  funinv_wf2 inject_wf int_seg_wf set_wf equal-wf-T-base compose_wf nat_wf equal_wf funinv-property int_seg_properties lelt_wf nat_properties decidable__equal_int satisfiable-full-omega-tt intformand_wf intformnot_wf intformeq_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_eq_lemma int_term_value_var_lemma int_formula_prop_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
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality setElimination rename dependent_set_memberEquality hypothesis natural_numberEquality because_Cache functionExtensionality applyEquality lambdaEquality sqequalRule imageMemberEquality baseClosed imageElimination functionEquality isect_memberEquality axiomEquality equalityTransitivity equalitySymmetry dependent_functionElimination setEquality independent_functionElimination hyp_replacement Error :applyLambdaEquality,  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)\}  ].  \mforall{}[g:\mBbbN{}n  {}\mrightarrow{}  \mBbbN{}n].    inv(f)  =  g  supposing  (f  o  g)  =  (\mlambda{}x.x)



Date html generated: 2016_10_21-AM-09_59_48
Last ObjectModification: 2016_07_12-AM-05_14_19

Theory : int_2


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