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: ℙ
, 
guard: {T}
, 
so_apply: x[s1;s2]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ 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: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s1;s2]
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
, 
subtype_rel: A ⊆r 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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