Nuprl Lemma : combinations-step

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


Proof




Definitions occuring in Statement :  combinations: C(n;m) nat: ifthenelse: if then else fi  eq_int: (i =z j) uall: [x:A]. B[x] multiply: m subtract: m natural_number: $n sqequal: 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: all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] prop: 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 ≥  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


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