Nuprl Lemma : not-Sierpinski-top
∀[x:Sierpinski]. ((¬(x = ⊤ ∈ Sierpinski)) 
⇒ (x = ⊥ ∈ Sierpinski))
Proof
Definitions occuring in Statement : 
Sierpinski: Sierpinski
, 
Sierpinski-top: ⊤
, 
Sierpinski-bottom: ⊥
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
Sierpinski: Sierpinski
, 
quotient: x,y:A//B[x; y]
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
Sierpinski-bottom: ⊥
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
not: ¬A
, 
false: False
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
ifthenelse: if b then t else f fi 
, 
assert: ↑b
Lemmas referenced : 
Sierpinski-unequal-1, 
Sierpinski_wf, 
quotient-member-eq, 
nat_wf, 
bool_wf, 
iff_wf, 
equal-wf-T-base, 
two-class-equiv-rel, 
Sierpinski-bottom_wf, 
eqtt_to_assert, 
Sierpinski-top_wf, 
equal-wf-base, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
bfalse_wf, 
not_wf, 
assert_elim, 
btrue_neq_bfalse
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
productElimination, 
thin, 
isect_memberFormation, 
lambdaFormation, 
pointwiseFunctionalityForEquality, 
hypothesis, 
sqequalRule, 
pertypeElimination, 
isectElimination, 
functionEquality, 
lambdaEquality, 
hypothesisEquality, 
baseClosed, 
because_Cache, 
independent_isectElimination, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
independent_pairFormation, 
functionExtensionality, 
rename, 
applyEquality, 
unionElimination, 
equalityElimination, 
voidElimination, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
cumulativity, 
productEquality, 
axiomEquality, 
applyLambdaEquality
Latex:
\mforall{}[x:Sierpinski].  ((\mneg{}(x  =  \mtop{}))  {}\mRightarrow{}  (x  =  \mbot{}))
Date html generated:
2019_10_31-AM-06_35_29
Last ObjectModification:
2017_07_28-AM-09_11_56
Theory : synthetic!topology
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