Nuprl Lemma : range_inf_wf
∀[I:{I:Interval| icompact(I)} ]. ∀[f:{x:ℝ| x ∈ I} ⟶ ℝ].
inf{f[x] | x ∈ I} ∈ ℝ supposing ∀x,y:{x:ℝ| x ∈ I} . ((x = y)
⇒ (f[x] = f[y]))
Proof
Definitions occuring in Statement :
range_inf: inf{f[x] | x ∈ I}
,
icompact: icompact(I)
,
i-member: r ∈ I
,
interval: Interval
,
req: x = y
,
real: ℝ
,
uimplies: b supposing a
,
uall: ∀[x:A]. B[x]
,
so_apply: x[s]
,
all: ∀x:A. B[x]
,
implies: P
⇒ Q
,
member: t ∈ T
,
set: {x:A| B[x]}
,
function: x:A ⟶ B[x]
Definitions unfolded in proof :
uall: ∀[x:A]. B[x]
,
uimplies: b supposing a
,
member: t ∈ T
,
all: ∀x:A. B[x]
,
sq_stable: SqStable(P)
,
implies: P
⇒ Q
,
squash: ↓T
,
subinterval: I ⊆ J
,
prop: ℙ
,
ifun: ifun(f;I)
,
real-fun: real-fun(f;a;b)
,
subtype_rel: A ⊆r B
,
so_lambda: λ2x.t[x]
,
and: P ∧ Q
,
so_apply: x[s]
,
cand: A c∧ B
,
range_inf: inf{f[x] | x ∈ I}
,
label: ...$L... t
,
rfun: I ⟶ℝ
,
exists: ∃x:A. B[x]
,
pi1: fst(t)
,
icompact: icompact(I)
Latex:
\mforall{}[I:\{I:Interval| icompact(I)\} ]. \mforall{}[f:\{x:\mBbbR{}| x \mmember{} I\} {}\mrightarrow{} \mBbbR{}].
inf\{f[x] | x \mmember{} I\} \mmember{} \mBbbR{} supposing \mforall{}x,y:\{x:\mBbbR{}| x \mmember{} I\} . ((x = y) {}\mRightarrow{} (f[x] = f[y]))
Date html generated:
2020_05_20-PM-00_15_14
Last ObjectModification:
2020_01_03-PM-02_33_08
Theory : reals
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