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: ℙ, 
guard: {T}, 
so_apply: x[s1;s2], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
or: P ∨ Q, 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
subtype_rel: A ⊆r B, 
rev_implies: P ⇐ Q, 
so_apply: x[s], 
so_apply: x[s1;s2], 
so_lambda: λ2x.t[x], 
prop: ℙ, 
member: t ∈ T, 
all: ∀x:A. B[x], 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
implies: P ⇒ 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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