Nuprl Lemma : sqequal-nil

∀[T:Type]. ∀[l:T List].  l ~ [] supposing l = [] ∈ (T List)


Proof




Definitions occuring in Statement :  nil: [],  list: T List,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  universe: Type,  sqequal: s ~ t,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  or: P ∨ Q,  cons: [a / b],  assert: ↑b,  ifthenelse: if b then t else f fi ,  btrue: tt,  bfalse: ff,  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  false: False,  uiff: uiff(P;Q),  top: Top,  prop: ℙ,  rev_implies: P ⇐ Q,  true: True,  not: ¬A
Lemmas referenced :  list-cases,  product_subtype_list,  iff_imp_equal_bool,  btrue_wf,  bfalse_wf,  assert_of_null,  null_cons_lemma,  istype-void,  true_wf,  false_wf,  btrue_neq_bfalse,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  hypothesisEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesis,  dependent_functionElimination,  unionElimination,  promote_hyp,  hypothesis_subsumption,  productElimination,  sqequalRule,  independent_isectElimination,  independent_pairFormation,  Error :lambdaFormation_alt,  equalityTransitivity,  equalitySymmetry,  Error :isect_memberEquality_alt,  voidElimination,  Error :universeIsType,  natural_numberEquality,  independent_functionElimination,  axiomSqEquality,  Error :equalityIsType3,  Error :inhabitedIsType,  baseClosed,  because_Cache,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[l:T  List].    l  \msim{}  []  supposing  l  =  []



Date html generated: 2019_06_20-PM-01_19_17
Last ObjectModification: 2018_09_30-PM-03_55_34

Theory : list_1


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