Nuprl Lemma : cons-has-member

[S:Type]. ∀a:S. ∀[b:S List]. ∃x:S. (x ∈ [a b])


Proof




Definitions occuring in Statement :  l_member: (x ∈ l) cons: [a b] list: List uall: [x:A]. B[x] all: x:A. B[x] exists: x:A. B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] exists: x:A. B[x] member: t ∈ T l_member: (x ∈ l) nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A implies:  Q top: Top select: L[n] cons: [a b] cand: c∧ B nat_plus: + less_than: a < b squash: T true: True guard: {T} uimplies: supposing a sq_stable: SqStable(P) prop:
Lemmas referenced :  istype-false istype-le length_of_cons_lemma istype-void add_nat_plus length_wf_nat istype-less_than cons_wf length_wf select_wf sq_stable__le l_member_wf list_wf istype-universe
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  Error :dependent_pairFormation_alt,  hypothesisEquality Error :dependent_set_memberEquality_alt,  natural_numberEquality sqequalRule independent_pairFormation hypothesis cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin because_Cache dependent_functionElimination Error :isect_memberEquality_alt,  voidElimination imageMemberEquality baseClosed Error :inhabitedIsType,  setElimination rename imageElimination productElimination Error :equalityIstype,  equalityTransitivity equalitySymmetry independent_functionElimination Error :productIsType,  independent_isectElimination Error :universeIsType,  instantiate universeEquality

Latex:
\mforall{}[S:Type].  \mforall{}a:S.  \mforall{}[b:S  List].  \mexists{}x:S.  (x  \mmember{}  [a  /  b])



Date html generated: 2019_06_20-PM-00_40_38
Last ObjectModification: 2019_03_06-AM-11_06_29

Theory : list_0


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