Nuprl Lemma : not_over_exists
∀[T:Type]. ∀[Q:T ⟶ ℙ].  uiff(¬(∃x:T. Q[x]);∀x:T. (¬Q[x]))
Proof
Definitions occuring in Statement : 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
not: ¬A
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
exists: ∃x:A. B[x]
, 
all: ∀x:A. B[x]
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
Lemmas referenced : 
not_wf, 
exists_wf, 
all_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
applyEquality, 
hypothesisEquality, 
cut, 
hypothesis, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
sqequalRule, 
universeEquality, 
because_Cache, 
Error :universeIsType, 
introduction, 
extract_by_obid, 
isectElimination, 
Error :functionIsType, 
functionEquality, 
cumulativity, 
Error :isect_memberFormation_alt, 
independent_pairFormation, 
lambdaFormation, 
independent_functionElimination, 
voidElimination, 
dependent_functionElimination, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
dependent_pairFormation
Latex:
\mforall{}[T:Type].  \mforall{}[Q:T  {}\mrightarrow{}  \mBbbP{}].    uiff(\mneg{}(\mexists{}x:T.  Q[x]);\mforall{}x:T.  (\mneg{}Q[x]))
Date html generated:
2019_06_20-AM-11_16_33
Last ObjectModification:
2018_09_26-AM-10_24_17
Theory : core_2
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