Nuprl Lemma : extensional-interval-to-bool-constant
∀a:ℝ. ∀b:{b:ℝ| a ≤ b} . ∀f:{x:ℝ| x ∈ [a, b]}  ⟶ 𝔹.
  ∀x,y:{x:ℝ| x ∈ [a, b]} .  f x = f y supposing ∀x,y:{x:ℝ| x ∈ [a, b]} .  ((x = y) 
⇒ f x = f y)
Proof
Definitions occuring in Statement : 
rccint: [l, u]
, 
i-member: r ∈ I
, 
rleq: x ≤ y
, 
req: x = y
, 
real: ℝ
, 
bool: 𝔹
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
uiff: uiff(P;Q)
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
i-member: r ∈ I
, 
rccint: [l, u]
, 
rev_uimplies: rev_uimplies(P;Q)
, 
top: Top
, 
iff: P 
⇐⇒ Q
, 
guard: {T}
Lemmas referenced : 
rmax_wf, 
rmin_wf, 
rleq-rmax, 
rmax_lb, 
sq_stable__rleq, 
rmin-rleq, 
rleq_wf, 
extensional-real-to-bool-constant, 
subtype_rel_self, 
real_wf, 
i-member_wf, 
rccint_wf, 
req_functionality, 
rmax_functionality, 
rmin_functionality, 
req_weakening, 
req_wf, 
bool_wf, 
member_rccint_lemma, 
istype-void, 
rmin_ub, 
rmax-req, 
rmin-req
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
isect_memberFormation_alt, 
introduction, 
cut, 
dependent_set_memberEquality_alt, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
setElimination, 
rename, 
hypothesis, 
productElimination, 
independent_pairFormation, 
because_Cache, 
independent_isectElimination, 
independent_functionElimination, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
productIsType, 
universeIsType, 
dependent_functionElimination, 
lambdaEquality_alt, 
applyEquality, 
setEquality, 
inhabitedIsType, 
setIsType, 
axiomEquality, 
functionIsTypeImplies, 
functionIsType, 
equalityIstype, 
isect_memberEquality_alt, 
voidElimination, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}a:\mBbbR{}.  \mforall{}b:\{b:\mBbbR{}|  a  \mleq{}  b\}  .  \mforall{}f:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}    {}\mrightarrow{}  \mBbbB{}.
    \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    f  x  =  f  y  supposing  \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    ((x  =  y)  {}\mRightarrow{}  f  x  =  f  y)
Date html generated:
2019_10_30-AM-07_17_36
Last ObjectModification:
2019_04_10-PM-03_55_34
Theory : reals
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