Nuprl Lemma : l_contains-append

∀[T:Type]. ∀A,B,C:T List.  (A @ B ⊆ C ⇐⇒ A ⊆ C ∧ B ⊆ C)


Proof




Definitions occuring in Statement :  l_contains: A ⊆ B,  append: as @ bs,  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  l_contains: A ⊆ B,  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  or: P ∨ Q,  prop: ℙ,  guard: {T},  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q
Lemmas referenced :  l_member_wf,  all_wf,  or_wf,  member_append,  append_wf,  iff_wf,  l_all_iff,  l_all_wf,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  independent_pairFormation,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  inlFormation,  introduction,  extract_by_obid,  isectElimination,  sqequalRule,  inrFormation,  because_Cache,  lambdaEquality,  functionEquality,  productElimination,  unionElimination,  productEquality,  addLevel,  setElimination,  rename,  setEquality,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}A,B,C:T  List.    (A  @  B  \msubseteq{}  C  \mLeftarrow{}{}\mRightarrow{}  A  \msubseteq{}  C  \mwedge{}  B  \msubseteq{}  C)



Date html generated: 2019_06_20-PM-01_26_43
Last ObjectModification: 2018_08_24-PM-11_16_47

Theory : list_1


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