Nuprl Lemma : permutation-nil-iff

[A:Type]. ∀L:A List. (permutation(A;[];L) ⇐⇒ [] ∈ (A List))


Proof




Definitions occuring in Statement :  permutation: permutation(T;L1;L2) nil: [] list: List uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q member: t ∈ T prop: rev_implies:  Q uimplies: supposing a or: P ∨ Q cons: [a b] top: Top ge: i ≥  le: A ≤ B satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A
Lemmas referenced :  permutation_wf nil_wf equal-wf-T-base list_wf permutation-length list-cases product_subtype_list length_of_nil_lemma length_of_cons_lemma non_neg_length satisfiable-full-omega-tt intformand_wf intformle_wf itermConstant_wf itermVar_wf intformeq_wf itermAdd_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_eq_lemma int_term_value_add_lemma int_formula_prop_wf permutation-nil
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation independent_pairFormation cut hypothesis introduction extract_by_obid sqequalHypSubstitution isectElimination thin cumulativity hypothesisEquality baseClosed universeEquality independent_isectElimination dependent_functionElimination unionElimination promote_hyp hypothesis_subsumption productElimination sqequalRule isect_memberEquality voidElimination voidEquality natural_numberEquality dependent_pairFormation lambdaEquality int_eqEquality intEquality computeAll hyp_replacement equalitySymmetry Error :applyLambdaEquality

Latex:
\mforall{}[A:Type].  \mforall{}L:A  List.  (permutation(A;[];L)  \mLeftarrow{}{}\mRightarrow{}  L  =  [])



Date html generated: 2016_10_21-AM-10_17_38
Last ObjectModification: 2016_07_12-AM-05_32_48

Theory : list_1


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