Nuprl Lemma : real-fun-implies-sfun-general
∀[I:Interval]. ∀[f:I ⟶ℝ].
  ∀x,y:{x:ℝ| x ∈ I} .  (f x ≠ f y 
⇒ x ≠ y) supposing ∀x,y:{x:ℝ| x ∈ I} .  ((x = y) 
⇒ ((f x) = (f y)))
Proof
Definitions occuring in Statement : 
rfun: I ⟶ℝ
, 
i-member: r ∈ I
, 
interval: Interval
, 
rneq: x ≠ y
, 
req: x = y
, 
real: ℝ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
rfun: I ⟶ℝ
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
or: P ∨ Q
, 
not: ¬A
, 
guard: {T}
, 
false: False
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
, 
top: Top
, 
cand: A c∧ B
, 
subinterval: I ⊆ J 
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
req_witness, 
i-member_wf, 
req_wf, 
real_wf, 
real-weak-Markov, 
rneq_wf, 
set_wf, 
all_wf, 
rfun_wf, 
interval_wf, 
rneq-cases, 
not_wf, 
rneq_irreflexivity, 
rneq_functionality, 
req_weakening, 
rmin-rmax-subinterval, 
sq_stable__i-member, 
rmin-rleq-rmax, 
rmin_wf, 
rmax_wf, 
equal_wf, 
member_rccint_lemma, 
rleq_wf, 
rmin_ub, 
rleq-rmax, 
rmin-rleq, 
rccint_wf, 
rmax_lb, 
req_functionality, 
rmin_functionality, 
rmax_functionality, 
rmin-req, 
rmax-req
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
extract_by_obid, 
isectElimination, 
applyEquality, 
setElimination, 
rename, 
dependent_set_memberEquality, 
hypothesis, 
because_Cache, 
independent_functionElimination, 
setEquality, 
lambdaFormation, 
independent_isectElimination, 
functionEquality, 
unionElimination, 
inlFormation, 
inrFormation, 
voidElimination, 
productElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
voidEquality, 
independent_pairFormation, 
productEquality
Latex:
\mforall{}[I:Interval].  \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}].
    \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    (f  x  \mneq{}  f  y  {}\mRightarrow{}  x  \mneq{}  y) 
    supposing  \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  ((f  x)  =  (f  y)))
Date html generated:
2017_10_03-AM-09_57_00
Last ObjectModification:
2017_08_31-AM-11_52_29
Theory : reals
Home
Index