Nuprl Lemma : length_of_null_list

∀[A:Type]. ∀[as:A List].  ||as|| = 0 ∈ ℤ supposing as = [] ∈ (A List)


Proof




Definitions occuring in Statement :  length: ||as||,  nil: [],  list: T List,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  prop: ℙ
Lemmas referenced :  length_of_nil_lemma,  equal-wf-T-base,  length_wf,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  hypothesis,  thin,  sqequalRule,  extract_by_obid,  natural_numberEquality,  hyp_replacement,  equalitySymmetry,  applyLambdaEquality,  sqequalHypSubstitution,  isectElimination,  intEquality,  hypothesisEquality,  baseClosed,  Error :universeIsType,  isect_memberEquality,  axiomEquality,  because_Cache,  equalityTransitivity,  universeEquality

Latex:
\mforall{}[A:Type].  \mforall{}[as:A  List].    ||as||  =  0  supposing  as  =  []



Date html generated: 2019_06_20-PM-00_39_53
Last ObjectModification: 2018_09_26-PM-02_12_29

Theory : list_0


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