Nuprl Lemma : count-combinations

n,m:ℕ.  Combination(n;ℕm) ~ ℕC(n;m)


This theorem is one of freek's list of 100 theorems



Proof




Definitions occuring in Statement :  combinations: C(n;m) combination: Combination(n;T) equipollent: B int_seg: {i..j-} nat: all: x:A. B[x] natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T uall: [x:A]. B[x] nat: ge: i ≥  decidable: Dec(P) or: P ∨ Q uimplies: supposing a not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top and: P ∧ Q prop: so_lambda: λ2x.t[x] so_apply: x[s] le: A ≤ B less_than': less_than'(a;b) eq_int: (i =z j) subtract: m ifthenelse: if then else fi  btrue: tt equipollent: B int_seg: {i..j-} lelt: i ≤ j < k less_than: a < b squash: T true: True biject: Bij(A;B;f) inject: Inj(A;B;f) surject: Surj(A;B;f) combination: Combination(n;T) cand: c∧ B subtype_rel: A ⊆B cons: [a b] guard: {T} iff: ⇐⇒ Q sq_type: SQType(T) bool: 𝔹 unit: Unit it: uiff: uiff(P;Q) bfalse: ff rev_implies:  Q nat_plus: + pi1: fst(t) pi2: snd(t) l_member: (x ∈ l)
Lemmas referenced :  nat_wf equipollent_wf combination_wf int_seg_wf subtract_wf combinations_wf_int nat_properties decidable__le full-omega-unsat intformand_wf intformnot_wf intformle_wf itermConstant_wf itermSubtract_wf itermVar_wf intformless_wf istype-int int_formula_prop_and_lemma istype-void 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_less_lemma int_formula_prop_wf le_wf less_than_wf primrec-wf2 all_wf combinations-step istype-false biject_wf list-cases length_of_nil_lemma nil_wf no_repeats_wf length_wf_nat set_subtype_base int_subtype_base product_subtype_list length_of_cons_lemma equal_wf squash_wf true_wf istype-universe subtype_rel_self iff_weakening_equal non_neg_length int_seg_properties intformeq_wf itermAdd_wf int_formula_prop_eq_lemma int_term_value_add_lemma subtype_rel-equal base_wf no_repeats_nil length_nil list_subtype_base lelt_wf decidable__equal_int subtype_base_sq eq_int_wf equal-wf-base bool_wf assert_wf bnot_wf not_wf itermMultiply_wf int_term_value_mul_lemma uiff_transitivity eqtt_to_assert assert_of_eq_int iff_transitivity iff_weakening_uiff eqff_to_assert assert_of_bnot equipollent-zero combination-decomp subtype_rel_set list_wf equal-wf-base-T equal-wf-T-base subtype_rel_list product_subtype_base pi1_wf_top reduce_tl_nil_lemma reduce_tl_cons_lemma reduce_hd_cons_lemma cons_wf no_repeats_cons no_repeats-settype l_member_wf select_wf equipollent_functionality_wrt_equipollent equipollent_weakening_ext-eq ext-eq_weakening equipollent-subtract-one id-biject product_functionality_wrt_equipollent_dependent equipollent_same combination_functionality equipollent-multiply combinations_wf product_functionality_wrt_equipollent_right
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut thin universeIsType because_Cache rename setElimination sqequalRule functionIsType introduction extract_by_obid hypothesis sqequalHypSubstitution isectElimination natural_numberEquality hypothesisEquality dependent_set_memberEquality_alt dependent_functionElimination unionElimination independent_isectElimination approximateComputation independent_functionElimination dependent_pairFormation_alt lambdaEquality_alt int_eqEquality isect_memberEquality_alt voidElimination independent_pairFormation setIsType inhabitedIsType imageMemberEquality baseClosed productIsType equalityIsType4 productElimination equalityTransitivity equalitySymmetry applyEquality intEquality promote_hyp hypothesis_subsumption imageElimination universeEquality instantiate applyLambdaEquality baseApply closedConclusion cumulativity equalityElimination equalityIsType1 dependent_pairEquality_alt setEquality productEquality independent_pairEquality multiplyEquality

Latex:
\mforall{}n,m:\mBbbN{}.    Combination(n;\mBbbN{}m)  \msim{}  \mBbbN{}C(n;m)



Date html generated: 2019_10_15-AM-11_16_03
Last ObjectModification: 2018_10_09-PM-02_12_24

Theory : general


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