Nuprl Lemma : nat-star-retract-property

s:ℕ ⟶ ℕ(∃n:ℕ0 < ⇐⇒ ∃n:ℕ0 < nat-star-retract(s) n)


Proof




Definitions occuring in Statement :  nat-star-retract: nat-star-retract(s) nat: less_than: a < b all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q apply: a function: x:A ⟶ B[x] natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q exists: x:A. B[x] member: t ∈ T prop: uall: [x:A]. B[x] so_lambda: λ2x.t[x] subtype_rel: A ⊆B so_apply: x[s] rev_implies:  Q nat-star: * guard: {T} int_seg: {i..j-} lelt: i ≤ j < k uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) false: False not: ¬A top: Top decidable: Dec(P) or: P ∨ Q le: A ≤ B less_than': less_than'(a;b) nat: ge: i ≥  nat-star-retract: nat-star-retract(s) bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff sq_type: SQType(T) bnot: ¬bb assert: b less_than: a < b squash: T
Lemmas referenced :  exists_wf nat_wf less_than_wf nat-star-retract_wf nat-star_wf int_seg_properties satisfiable-full-omega-tt intformand_wf intformless_wf itermVar_wf itermConstant_wf intformle_wf int_formula_prop_and_lemma int_formula_prop_less_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_le_lemma int_formula_prop_wf int_seg_wf decidable__equal_int subtract_wf int_seg_subtype false_wf decidable__le intformnot_wf itermSubtract_wf intformeq_wf int_formula_prop_not_lemma int_term_value_subtract_lemma int_formula_prop_eq_lemma le_wf all_wf int_seg_subtype_nat decidable__lt lelt_wf set_wf primrec-wf2 nat_properties itermAdd_wf int_term_value_add_lemma decidable__exists_int_seg bl-exists_wf upto_wf l_member_wf lt_int_wf bool_wf eqtt_to_assert assert-bl-exists l_exists_functionality assert_wf iff_weakening_uiff subtype_rel_set assert_of_lt_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot l_exists_wf l_exists_iff bnot_wf not_wf bool_cases iff_transitivity assert_of_bnot
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation independent_pairFormation sqequalHypSubstitution productElimination thin cut introduction extract_by_obid isectElimination hypothesis sqequalRule lambdaEquality natural_numberEquality applyEquality functionExtensionality hypothesisEquality because_Cache setElimination rename functionEquality independent_isectElimination dependent_pairFormation int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality computeAll unionElimination addLevel equalityTransitivity equalitySymmetry applyLambdaEquality levelHypothesis hypothesis_subsumption dependent_set_memberEquality addEquality independent_functionElimination instantiate setEquality equalityElimination promote_hyp cumulativity imageElimination impliesFunctionality

Latex:
\mforall{}s:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}.  (\mexists{}n:\mBbbN{}.  0  <  s  n  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbN{}.  0  <  nat-star-retract(s)  n)



Date html generated: 2017_04_17-AM-09_55_20
Last ObjectModification: 2017_02_27-PM-05_49_45

Theory : continuity


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