Nuprl Lemma : l_member-permutation

[T:Type]. ∀L:T List. ∀x:T.  ((x ∈ L)  (∃L':T List. permutation(T;L;[x L'])))


Proof




Definitions occuring in Statement :  permutation: permutation(T;L1;L2) l_member: (x ∈ l) cons: [a b] list: List uall: [x:A]. B[x] all: x:A. B[x] exists: x:A. B[x] implies:  Q universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] implies:  Q prop: so_apply: x[s] uimplies: supposing a not: ¬A false: False iff: ⇐⇒ Q and: P ∧ Q or: P ∨ Q exists: x:A. B[x] l_member: (x ∈ l) cand: c∧ B append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) top: Top so_apply: x[s1;s2;s3]
Lemmas referenced :  list_induction all_wf l_member_wf exists_wf list_wf permutation_wf cons_wf null_nil_lemma btrue_wf member-implies-null-eq-bfalse nil_wf btrue_neq_bfalse cons_member permutation_weakening and_wf equal_wf append_functionality_wrt_permutation list_ind_cons_lemma list_ind_nil_lemma permutation_transitivity permutation-rotate
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut thin lemma_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality functionEquality hypothesis independent_functionElimination rename because_Cache dependent_functionElimination universeEquality independent_isectElimination equalityTransitivity equalitySymmetry voidElimination productElimination unionElimination dependent_pairFormation dependent_set_memberEquality independent_pairFormation applyEquality setElimination setEquality isect_memberEquality voidEquality

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}x:T.    ((x  \mmember{}  L)  {}\mRightarrow{}  (\mexists{}L':T  List.  permutation(T;L;[x  /  L'])))



Date html generated: 2016_05_14-PM-02_21_44
Last ObjectModification: 2015_12_26-PM-04_28_00

Theory : list_1


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