Nuprl Lemma : connex_iff_trichot

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

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}a,b:T.    Dec(R[a;b]))
    {}\mRightarrow{}  (Connex(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_23
Last ObjectModification: 2018_10_04-PM-04_36_32

Theory : rel_1


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