Nuprl Lemma : cos-sin-equation-non-constant3
∀f,g:ℝ ⟶ ℝ.
  ((∀x,y:ℝ.  ((x = y) 
⇒ (f(x) = f(y))))
  
⇒ (∀x,y:ℝ.  ((x = y) 
⇒ (g(x) = g(y))))
  
⇒ (∃a,b:ℝ. f(a) ≠ f(b))
  
⇒ (∀x,y:ℝ.  (f(x - y) = ((f(x) * f(y)) + (g(x) * g(y)))))
  
⇒ (∃b:ℝ. (r0_∫-b -(g(x)) dx ≠ r0 ∧ f(b) ≠ r1))
  
⇒ (∃a:ℝ. (a ≠ r0 ∧ (∀x:ℝ. (f(x) = rcos(a * x))) ∧ (∀x:ℝ. (g(x) = rsin(a * x))))))
Proof
Definitions occuring in Statement : 
rfun-ap: f(x)
, 
rcos: rcos(x)
, 
rsin: rsin(x)
, 
integral: a_∫-b f[x] dx
, 
rneq: x ≠ y
, 
rsub: x - y
, 
req: x = y
, 
rmul: a * b
, 
rminus: -(x)
, 
radd: a + b
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
rfun-ap: f(x)
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
prop: ℙ
, 
rfun: I ⟶ℝ
, 
ifun: ifun(f;I)
, 
top: Top
, 
real-fun: real-fun(f;a;b)
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
iff: P 
⇐⇒ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
stable: Stable{P}
, 
rfun-eq: rfun-eq(I;f;g)
, 
r-ap: f(x)
, 
rat_term_to_real: rat_term_to_real(f;t)
, 
rtermDivide: num "/" denom
, 
rat_term_ind: rat_term_ind, 
rtermVar: rtermVar(var)
, 
pi1: fst(t)
, 
true: True
, 
rtermMultiply: left "*" right
, 
rtermConstant: "const"
, 
pi2: snd(t)
, 
rdiv: (x/y)
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
, 
rtermSubtract: left "-" right
, 
cand: A c∧ B
, 
real-sfun: real-sfun(f;a;b)
Lemmas referenced : 
cos-sin-equation-non-constant1, 
rless-implies-rless, 
rsub_wf, 
rfun-ap_wf, 
int-to-real_wf, 
rless_wf, 
real_wf, 
rneq_wf, 
rminus_wf, 
i-member_wf, 
rccint_wf, 
rmin_wf, 
rmax_wf, 
left_endpoint_rccint_lemma, 
istype-void, 
right_endpoint_rccint_lemma, 
req_functionality, 
rminus_functionality, 
rfun-ap_functionality, 
req_weakening, 
req_wf, 
ifun_wf, 
rccint-icompact, 
rmin-rleq-rmax, 
integral_wf, 
radd_wf, 
rmul_wf, 
itermSubtract_wf, 
itermConstant_wf, 
itermVar_wf, 
req-iff-rsub-is-0, 
real_polynomial_null, 
istype-int, 
real_term_value_sub_lemma, 
real_term_value_const_lemma, 
real_term_value_var_lemma, 
rsin_wf, 
stable_req, 
rdiv_wf, 
false_wf, 
rcos_wf, 
not_wf, 
minimal-double-negation-hyp-elim, 
minimal-not-not-excluded-middle, 
ftc-total-integral, 
derivative-function-rmul-const, 
rsin_functionality, 
derivative-rcos, 
riiint_wf, 
derivative_functionality, 
rmul_functionality, 
istype-true, 
member_riiint_lemma, 
derivative-mul, 
derivative-const, 
assert-rat-term-eq2, 
rtermMultiply_wf, 
rtermDivide_wf, 
rtermConstant_wf, 
rtermVar_wf, 
rmul_preserves_req, 
rinv_wf2, 
itermMultiply_wf, 
itermAdd_wf, 
itermMinus_wf, 
req_transitivity, 
rmul-rinv3, 
real_term_value_mul_lemma, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
iff_weakening_uiff, 
req_inversion, 
rcos_functionality, 
derivative-rsin, 
derivative_unique, 
iproper-riiint, 
req-implies-req, 
rcos0, 
rsub_functionality, 
rdiv_functionality, 
radd_functionality, 
rmul-rinv, 
rneq_functionality, 
rtermSubtract_wf, 
stable__and, 
all_wf, 
stable__all, 
real-fun-implies-sfun, 
rleq_wf, 
member_rccint_lemma, 
rmin-rleq, 
rleq-rmax, 
rmul-nonzero
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
sqequalRule, 
productElimination, 
unionElimination, 
inlFormation_alt, 
isectElimination, 
natural_numberEquality, 
independent_isectElimination, 
universeIsType, 
inrFormation_alt, 
productIsType, 
dependent_set_memberEquality_alt, 
lambdaEquality_alt, 
setElimination, 
rename, 
setIsType, 
inhabitedIsType, 
isect_memberEquality_alt, 
voidElimination, 
because_Cache, 
closedConclusion, 
equalityTransitivity, 
equalitySymmetry, 
functionIsType, 
approximateComputation, 
int_eqEquality, 
unionEquality, 
productEquality, 
functionEquality, 
unionIsType, 
applyEquality, 
independent_pairFormation, 
minusEquality, 
equalityIstype, 
dependent_pairFormation_alt, 
promote_hyp
Latex:
\mforall{}f,g:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  (\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (g(x)  =  g(y))))
    {}\mRightarrow{}  (\mexists{}a,b:\mBbbR{}.  f(a)  \mneq{}  f(b))
    {}\mRightarrow{}  (\mforall{}x,y:\mBbbR{}.    (f(x  -  y)  =  ((f(x)  *  f(y))  +  (g(x)  *  g(y)))))
    {}\mRightarrow{}  (\mexists{}b:\mBbbR{}.  (r0\_\mint{}\msupminus{}b  -(g(x))  dx  \mneq{}  r0  \mwedge{}  f(b)  \mneq{}  r1))
    {}\mRightarrow{}  (\mexists{}a:\mBbbR{}.  (a  \mneq{}  r0  \mwedge{}  (\mforall{}x:\mBbbR{}.  (f(x)  =  rcos(a  *  x)))  \mwedge{}  (\mforall{}x:\mBbbR{}.  (g(x)  =  rsin(a  *  x))))))
Date html generated:
2019_10_31-AM-06_25_00
Last ObjectModification:
2019_04_02-PM-10_27_45
Theory : reals_2
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