Nuprl Lemma : atan_wf
∀[a:{2...}]. ∀[x:ℝ].  atan(a;x) ∈ {y:ℝ| arctangent(x) = y}  supposing |x| ≤ (r1/r(a))
Proof
Definitions occuring in Statement : 
atan: atan(a;x)
, 
arctangent: arctangent(x)
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rabs: |x|
, 
req: x = y
, 
int-to-real: r(n)
, 
real: ℝ
, 
int_upper: {i...}
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
, 
natural_number: $n
Definitions unfolded in proof : 
top: Top
, 
false: False
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
not: ¬A
, 
decidable: Dec(P)
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
rneq: x ≠ y
, 
int_upper: {i...}
, 
atan: atan(a;x)
, 
guard: {T}
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
and: P ∧ Q
, 
true: True
, 
less_than': less_than'(a;b)
, 
squash: ↓T
, 
less_than: a < b
, 
nat_plus: ℕ+
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
int_upper_wf, 
real_wf, 
rless_wf, 
int_formula_prop_wf, 
int_formula_prop_le_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
intformle_wf, 
itermVar_wf, 
itermConstant_wf, 
intformless_wf, 
intformnot_wf, 
intformand_wf, 
full-omega-unsat, 
decidable__lt, 
int_upper_properties, 
rless-int, 
int-to-real_wf, 
rdiv_wf, 
rabs_wf, 
rleq_wf, 
req_wf, 
regular-int-seq_wf, 
accelerate_wf, 
req_inversion, 
nat_plus_wf, 
atan_approx_wf, 
arctangent_wf, 
less_than_wf, 
rational-approx-implies-req, 
atan_approx-property
Rules used in proof : 
voidEquality, 
voidElimination, 
isect_memberEquality, 
intEquality, 
int_eqEquality, 
dependent_pairFormation, 
approximateComputation, 
unionElimination, 
dependent_functionElimination, 
inrFormation, 
because_Cache, 
rename, 
setElimination, 
equalitySymmetry, 
equalityTransitivity, 
axiomEquality, 
productElimination, 
independent_isectElimination, 
lambdaFormation, 
independent_functionElimination, 
lambdaEquality, 
hypothesis, 
baseClosed, 
imageMemberEquality, 
independent_pairFormation, 
sqequalRule, 
natural_numberEquality, 
dependent_set_memberEquality, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[a:\{2...\}].  \mforall{}[x:\mBbbR{}].    atan(a;x)  \mmember{}  \{y:\mBbbR{}|  arctangent(x)  =  y\}    supposing  |x|  \mleq{}  (r1/r(a))
Date html generated:
2018_05_22-PM-03_05_54
Last ObjectModification:
2018_05_20-PM-11_20_24
Theory : reals_2
Home
Index