Nuprl Lemma : combinations-step

∀[n,m:ℕ].  (C(n;m) ~ if (n =z 0) then 1 else m * C(n - 1;m - 1) fi )


Proof




Definitions occuring in Statement :  combinations: C(n;m),  nat: ℕ,  ifthenelse: if b then t else f fi ,  eq_int: (i =z j),  uall: ∀[x:A]. B[x],  multiply: n * m,  subtract: n - m,  natural_number: $n,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  combinations: C(n;m),  combinations_aux: combinations_aux(b;n;m),  nat: ℕ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  prop: ℙ,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  le: A ≤ B,  less_than': less_than'(a;b),  not: ¬A,  ge: i ≥ j ,  int_upper: {i...},  has-value: (a)↓,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top
Lemmas referenced :  nat_wf,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  int_upper_subtype_nat,  false_wf,  le_wf,  nat_properties,  nequal-le-implies,  zero-add,  value-type-has-value,  int-value-type,  int_subtype_base,  subtract_wf,  combinations_aux_linear,  int_upper_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermSubtract_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_subtract_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  decidable__equal_int,  multiply-is-int-iff,  intformeq_wf,  itermMultiply_wf,  int_formula_prop_eq_lemma,  int_term_value_mul_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesis,  sqequalAxiom,  extract_by_obid,  sqequalRule,  sqequalHypSubstitution,  isect_memberEquality,  isectElimination,  thin,  hypothesisEquality,  because_Cache,  setElimination,  rename,  natural_numberEquality,  lambdaFormation,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  dependent_pairFormation,  promote_hyp,  dependent_functionElimination,  instantiate,  cumulativity,  independent_functionElimination,  voidElimination,  hypothesis_subsumption,  dependent_set_memberEquality,  independent_pairFormation,  callbyvalueReduce,  intEquality,  multiplyEquality,  lambdaEquality,  int_eqEquality,  voidEquality,  computeAll,  pointwiseFunctionality,  baseApply,  closedConclusion,  baseClosed

Latex:
\mforall{}[n,m:\mBbbN{}].    (C(n;m)  \msim{}  if  (n  =\msubz{}  0)  then  1  else  m  *  C(n  -  1;m  -  1)  fi  )



Date html generated: 2018_05_21-PM-08_09_16
Last ObjectModification: 2017_07_26-PM-05_44_57

Theory : general


Home Index