Nuprl Lemma : no_repeats-l_member!

[T:Type]. ∀l:T List. ∀x:T. ((x ∈ l) ⇐⇒ (x ∈l)) supposing no_repeats(T;l)


Proof




Definitions occuring in Statement :  l_member!: (x ∈l) no_repeats: no_repeats(T;l) l_member: (x ∈ l) list: List uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] uimplies: supposing a member: t ∈ T implies:  Q iff: ⇐⇒ Q and: P ∧ Q l_member: (x ∈ l) exists: x:A. B[x] cand: c∧ B l_member!: (x ∈l) nat: no_repeats: no_repeats(T;l) decidable: Dec(P) or: P ∨ Q not: ¬A squash: T guard: {T} false: False satisfiable_int_formula: satisfiable_int_formula(fmla) top: Top prop: subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] sq_stable: SqStable(P) ge: i ≥  rev_implies:  Q
Lemmas referenced :  no_repeats_witness decidable__equal_int satisfiable-full-omega-tt intformand_wf intformeq_wf itermVar_wf intformnot_wf int_formula_prop_and_lemma int_formula_prop_eq_lemma int_term_value_var_lemma int_formula_prop_not_lemma int_formula_prop_wf equal-wf-base set_subtype_base le_wf int_subtype_base sq_stable__le decidable__le intformle_wf itermConstant_wf int_formula_prop_le_lemma int_term_value_constant_lemma equal_wf select_wf nat_properties less_than_wf length_wf nat_wf all_wf l_member_wf l_member!_wf no_repeats_wf list_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality independent_functionElimination hypothesis rename independent_pairFormation productElimination dependent_pairFormation dependent_set_memberEquality dependent_functionElimination setElimination because_Cache unionElimination independent_isectElimination applyLambdaEquality sqequalRule imageMemberEquality baseClosed imageElimination natural_numberEquality lambdaEquality int_eqEquality intEquality isect_memberEquality voidElimination voidEquality computeAll applyEquality equalityTransitivity equalitySymmetry cumulativity productEquality functionEquality universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}l:T  List.  \mforall{}x:T.  ((x  \mmember{}  l)  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}!  l))  supposing  no\_repeats(T;l)



Date html generated: 2017_04_17-AM-07_29_12
Last ObjectModification: 2017_02_27-PM-04_07_36

Theory : list_1


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