Nuprl Lemma : length_zip

[T1,T2:Type]. ∀[as:T1 List]. ∀[bs:T2 List].  ||zip(as;bs)|| ||as|| ∈ ℤ supposing ||as|| ||bs|| ∈ ℤ


Proof




Definitions occuring in Statement :  zip: zip(as;bs) length: ||as|| list: List uimplies: supposing a uall: [x:A]. B[x] int: universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T so_lambda: λ2x.t[x] uimplies: supposing a prop: so_apply: x[s] implies:  Q zip: zip(as;bs) list_ind: list_ind nil: [] it: all: x:A. B[x] so_lambda: so_lambda(x,y,z.t[x; y; z]) top: Top so_apply: x[s1;s2;s3] squash: T guard: {T} decidable: Dec(P) or: P ∨ Q false: False uiff: uiff(P;Q) and: P ∧ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A true: True subtype_rel: A ⊆B iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  list_induction uall_wf list_wf isect_wf equal_wf length_wf zip_wf equal-wf-base-T equal-wf-T-base nil_wf length_of_nil_lemma list_ind_nil_lemma equal-wf-base length_of_cons_lemma cons_wf list_ind_cons_lemma squash_wf true_wf add_functionality_wrt_eq decidable__equal_int add-is-int-iff satisfiable-full-omega-tt intformand_wf intformnot_wf intformeq_wf itermVar_wf itermAdd_wf itermConstant_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_eq_lemma int_term_value_var_lemma int_term_value_add_lemma int_term_value_constant_lemma int_formula_prop_wf false_wf iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut thin extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality cumulativity hypothesis intEquality because_Cache productEquality independent_functionElimination baseClosed voidEquality dependent_functionElimination isect_memberEquality voidElimination equalityTransitivity equalitySymmetry lambdaFormation rename addEquality natural_numberEquality axiomEquality applyEquality imageElimination independent_isectElimination unionElimination pointwiseFunctionality promote_hyp baseApply closedConclusion productElimination dependent_pairFormation int_eqEquality independent_pairFormation computeAll imageMemberEquality universeEquality

Latex:
\mforall{}[T1,T2:Type].  \mforall{}[as:T1  List].  \mforall{}[bs:T2  List].    ||zip(as;bs)||  =  ||as||  supposing  ||as||  =  ||bs||



Date html generated: 2017_04_17-AM-08_55_08
Last ObjectModification: 2017_02_27-PM-05_10_44

Theory : list_1


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