Nuprl Lemma : l_disjoint_singleton

[T:Type]. ∀[a:T List]. ∀[x:T].  uiff(l_disjoint(T;a;[x]);¬(x ∈ a))


Proof




Definitions occuring in Statement :  l_disjoint: l_disjoint(T;l1;l2) l_member: (x ∈ l) cons: [a b] nil: [] list: List uiff: uiff(P;Q) uall: [x:A]. B[x] not: ¬A universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] l_disjoint: l_disjoint(T;l1;l2) uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a member: t ∈ T not: ¬A implies:  Q false: False prop: so_lambda: λ2x.t[x] so_apply: x[s] all: x:A. B[x] iff: ⇐⇒ Q rev_implies:  Q cand: c∧ B
Lemmas referenced :  l_member_wf all_wf not_wf equal_wf member_singleton cons_wf nil_wf uiff_wf list_wf and_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation cut independent_pairFormation introduction lambdaFormation thin hypothesis sqequalHypSubstitution independent_functionElimination voidElimination extract_by_obid isectElimination hypothesisEquality sqequalRule lambdaEquality dependent_functionElimination productEquality productElimination because_Cache addLevel independent_isectElimination cumulativity universeEquality hyp_replacement equalitySymmetry dependent_set_memberEquality applyLambdaEquality setElimination rename

Latex:
\mforall{}[T:Type].  \mforall{}[a:T  List].  \mforall{}[x:T].    uiff(l\_disjoint(T;a;[x]);\mneg{}(x  \mmember{}  a))



Date html generated: 2019_06_20-PM-01_27_16
Last ObjectModification: 2018_08_24-PM-11_25_52

Theory : list_1


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