Nuprl Lemma : list_decomp_reverse

[T:Type]. ∀L:T List. ∃x:T. ∃L':T List. (L (L' [x]) ∈ (T List)) supposing 0 < ||L||


Proof




Definitions occuring in Statement :  length: ||as|| append: as bs cons: [a b] nil: [] list: List less_than: a < b uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] exists: x:A. B[x] natural_number: $n universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] uimplies: supposing a prop: so_apply: x[s] implies:  Q less_than: a < b squash: T less_than': less_than'(a;b) false: False and: P ∧ Q top: Top or: P ∨ Q cons: [a b] exists: x:A. B[x] append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] ge: i ≥  decidable: Dec(P) le: A ≤ B not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) true: True
Lemmas referenced :  list_induction isect_wf less_than_wf length_wf exists_wf list_wf equal_wf append_wf cons_wf nil_wf length_of_nil_lemma member-less_than length_of_cons_lemma list-cases product_subtype_list list_ind_nil_lemma non_neg_length decidable__lt full-omega-unsat intformand_wf intformnot_wf intformless_wf itermConstant_wf itermAdd_wf itermVar_wf intformle_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_add_lemma int_term_value_var_lemma int_formula_prop_le_lemma int_formula_prop_wf list_ind_cons_lemma squash_wf true_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality natural_numberEquality hypothesis independent_functionElimination imageElimination productElimination voidElimination because_Cache independent_isectElimination rename Error :universeIsType,  dependent_functionElimination isect_memberEquality voidEquality addEquality universeEquality unionElimination promote_hyp hypothesis_subsumption dependent_pairFormation approximateComputation int_eqEquality intEquality independent_pairFormation applyEquality equalityTransitivity equalitySymmetry imageMemberEquality baseClosed

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mexists{}x:T.  \mexists{}L':T  List.  (L  =  (L'  @  [x]))  supposing  0  <  ||L||



Date html generated: 2019_06_20-PM-01_45_27
Last ObjectModification: 2018_09_26-PM-02_54_49

Theory : list_1


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