Nuprl Lemma : l-union-contained

∀[T:Type]. ∀eq:EqDecider(T). ∀as,bs,cs:T List.  (as ⋃ bs ⊆ cs ⇐⇒ as ⊆ cs ∧ bs ⊆ cs)


Proof




Definitions occuring in Statement :  l-union: as ⋃ bs,  l_contains: A ⊆ B,  list: T List,  deq: EqDecider(T),  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,  and_wf,  member-union,  l-union_wf,  iff_wf,  l_all_iff,  l_all_wf,  list_wf,  deq_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  independent_pairFormation,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  inlFormation,  lemma_by_obid,  isectElimination,  sqequalRule,  inrFormation,  because_Cache,  lambdaEquality,  functionEquality,  productElimination,  unionElimination,  addLevel,  impliesFunctionality,  allFunctionality,  allLevelFunctionality,  impliesLevelFunctionality,  cumulativity,  productEquality,  setElimination,  rename,  setEquality,  andLevelFunctionality,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}eq:EqDecider(T).  \mforall{}as,bs,cs:T  List.    (as  \mcup{}  bs  \msubseteq{}  cs  \mLeftarrow{}{}\mRightarrow{}  as  \msubseteq{}  cs  \mwedge{}  bs  \msubseteq{}  cs)



Date html generated: 2016_05_14-PM-03_24_47
Last ObjectModification: 2015_12_26-PM-06_22_04

Theory : decidable!equality


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