Nuprl Lemma : combinations-choose

[m,n:ℕ].  C(m;n) (choose(n;m) (m)!) ∈ ℤ supposing m ≤ n


Proof




Definitions occuring in Statement :  combinations: C(n;m) fact: (n)! nat: uimplies: supposing a uall: [x:A]. B[x] le: A ≤ B multiply: m int: equal: t ∈ T choose: choose(n;i)
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T and: P ∧ Q uimplies: supposing a nat: not: ¬A implies:  Q false: False all: x:A. B[x] or: P ∨ Q sq_type: SQType(T) guard: {T} uiff: uiff(P;Q) ifthenelse: if then else fi  btrue: tt iff: ⇐⇒ Q rev_implies:  Q bfalse: ff int_iseg: {i...j} cand: c∧ B ge: i ≥  decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top prop: subtype_rel: A ⊆B nat_plus: +
Lemmas referenced :  combinations-formula istype-le istype-nat le_int_wf assert_wf bnot_wf not_wf le_wf istype-assert istype-void bool_cases subtype_base_sq bool_wf bool_subtype_base eqtt_to_assert assert_of_le_int eqff_to_assert iff_transitivity iff_weakening_uiff assert_of_bnot choose-formula mul_cancel_in_eq choose_wf nat_properties decidable__le full-omega-unsat intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf istype-int int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf fact_wf subtract_wf itermSubtract_wf int_term_value_subtract_lemma decidable__equal_int multiply-is-int-iff intformeq_wf itermMultiply_wf int_formula_prop_eq_lemma int_term_value_mul_lemma false_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality productElimination independent_isectElimination setElimination rename because_Cache equalityTransitivity equalitySymmetry inhabitedIsType sqequalRule functionIsType independent_functionElimination voidElimination dependent_functionElimination unionElimination instantiate cumulativity independent_pairFormation lambdaFormation_alt multiplyEquality dependent_set_memberEquality_alt natural_numberEquality approximateComputation dependent_pairFormation_alt lambdaEquality_alt int_eqEquality isect_memberEquality_alt universeIsType productIsType applyEquality pointwiseFunctionality promote_hyp baseApply closedConclusion baseClosed

Latex:
\mforall{}[m,n:\mBbbN{}].    C(m;n)  =  (choose(n;m)  *  (m)!)  supposing  m  \mleq{}  n



Date html generated: 2019_10_15-AM-11_21_41
Last ObjectModification: 2018_11_30-PM-01_15_46

Theory : general


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