Nuprl Lemma : uconnex_iff_trichot

[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].
  ((∀[a,b:T].  Dec(R[a;b]))
   (uconnex(T; x,y.R[x;y])
     ⇐⇒ {∀[a,b:T].  (strict_part(x,y.R[x;y];a;b) ∨ Symmetrize(x,y.R[x;y];a;b) ∨ strict_part(x,y.R[x;y];b;a))}))


Proof




Definitions occuring in Statement :  uconnex: uconnex(T; x,y.R[x; y]) strict_part: strict_part(x,y.R[x; y];a;b) symmetrize: Symmetrize(x,y.R[x; y];a;b) decidable: Dec(P) uall: [x:A]. B[x] prop: guard: {T} so_apply: x[s1;s2] iff: ⇐⇒ Q implies:  Q or: P ∨ Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  guard: {T} strict_part: strict_part(x,y.R[x; y];a;b) symmetrize: Symmetrize(x,y.R[x; y];a;b) uconnex: uconnex(T; x,y.R[x; y]) uall: [x:A]. B[x] implies:  Q iff: ⇐⇒ Q and: P ∧ Q member: t ∈ T prop: so_lambda: λ2x.t[x] so_apply: x[s1;s2] so_apply: x[s] rev_implies:  Q subtype_rel: A ⊆B or: P ∨ Q decidable: Dec(P) not: ¬A false: False
Lemmas referenced :  uall_wf or_wf subtype_rel_self not_wf decidable_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep Error :isect_memberFormation_alt,  lambdaFormation independent_pairFormation Error :inhabitedIsType,  hypothesisEquality Error :universeIsType,  cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin lambdaEquality applyEquality hypothesis productEquality instantiate universeEquality because_Cache Error :functionIsType,  unionElimination inrFormation inlFormation functionExtensionality independent_functionElimination voidElimination productElimination

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}[a,b:T].    Dec(R[a;b]))
    {}\mRightarrow{}  (uconnex(T;  x,y.R[x;y])
          \mLeftarrow{}{}\mRightarrow{}  \{\mforall{}[a,b:T].
                        (strict\_part(x,y.R[x;y];a;b)
                        \mvee{}  Symmetrize(x,y.R[x;y];a;b)
                        \mvee{}  strict\_part(x,y.R[x;y];b;a))\}))



Date html generated: 2019_06_20-PM-00_29_25
Last ObjectModification: 2018_09_26-PM-00_01_01

Theory : rel_1


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