:: Several Integrability Formulas of Special Functions
:: by Cuiying Peng , Fuguo Ge and Xiquan Liang
::
:: Received August 28, 2007
:: Copyright (c) 2007-2012 Association of Mizar Users


begin

Lm1:  sin (PI / 4) > 0
proofend;

Lm2:  sin (- (PI / 4)) < 0
proofend;

theorem Th1: :: INTEGRA8:1
for x being Real
for n being Element of NAT holds sin (x + ((2 * n) * PI)) = sin x
proofend;

theorem Th2: :: INTEGRA8:2
for x being Real
for n being Element of NAT holds sin (x + (((2 * n) + 1) * PI)) = - (sin x)
proofend;

theorem Th3: :: INTEGRA8:3
for x being Real
for n being Element of NAT holds cos (x + ((2 * n) * PI)) = cos x
proofend;

theorem Th4: :: INTEGRA8:4
for x being Real
for n being Element of NAT holds cos (x + (((2 * n) + 1) * PI)) = - (cos x)
proofend;

theorem Th5: :: INTEGRA8:5
for x being Real st sin (x / 2) >= 0 holds
sin (x / 2) = sqrt ((1 - (cos x)) / 2)
proofend;

theorem Th6: :: INTEGRA8:6
for x being Real st sin (x / 2) < 0 holds
sin (x / 2) = - (sqrt ((1 - (cos x)) / 2))
proofend;

theorem Th7: :: INTEGRA8:7
sin (PI / 4) = (sqrt 2) / 2
proofend;

theorem Th8: :: INTEGRA8:8
sin (- (PI / 4)) = - ((sqrt 2) / 2)
proofend;

theorem Th9: :: INTEGRA8:9
[.(- ((sqrt 2) / 2)),((sqrt 2) / 2).] c= ].(- 1),1.[
proofend;

theorem Th10: :: INTEGRA8:10
arcsin ((sqrt 2) / 2) = PI / 4
proofend;

theorem Th11: :: INTEGRA8:11
arcsin (- ((sqrt 2) / 2)) = - (PI / 4)
proofend;

theorem Th12: :: INTEGRA8:12
for x being Real st cos (x / 2) >= 0 holds
cos (x / 2) = sqrt ((1 + (cos x)) / 2)
proofend;

Lm3:  cos (PI / 4) > 0
proofend;

theorem Th13: :: INTEGRA8:13
cos (PI / 4) = (sqrt 2) / 2
proofend;

theorem Th14: :: INTEGRA8:14
cos ((3 * PI) / 4) = - ((sqrt 2) / 2)
proofend;

theorem Th15: :: INTEGRA8:15
arccos ((sqrt 2) / 2) = PI / 4
proofend;

theorem Th16: :: INTEGRA8:16
arccos (- ((sqrt 2) / 2)) = (3 * PI) / 4
proofend;

theorem Th17: :: INTEGRA8:17
sinh . 1 = ((number_e ^2) - 1) / (2 * number_e)
proofend;

theorem Th18: :: INTEGRA8:18
cosh . 0 = 1
proofend;

theorem Th19: :: INTEGRA8:19
cosh . 1 = ((number_e ^2) + 1) / (2 * number_e)
proofend;

Lm4:  for f1, f2 being PartFunc of REAL,REAL holds (- f1) (#) (- f2) = f1 (#) f2
proofend;

theorem Th20: :: INTEGRA8:20
for L1 being LinearFunc holds - L1 is LinearFunc
proofend;

theorem Th21: :: INTEGRA8:21
for R1 being RestFunc holds - R1 is RestFunc
proofend;

theorem Th22: :: INTEGRA8:22
for f1 being PartFunc of REAL,REAL
for x0 being Real st f1 is_differentiable_in x0 holds
( - f1 is_differentiable_in x0 &amp; diff ((- f1),x0) = - (diff (f1,x0)) )
proofend;

theorem Th23: :: INTEGRA8:23
for f1 being PartFunc of REAL,REAL
for Z being open Subset of REAL st Z c= dom (- f1) &amp; f1 is_differentiable_on Z holds
( - f1 is_differentiable_on Z &amp; ( for x being Real st x in Z holds
((- f1) `| Z) . x = - (diff (f1,x)) ) )
proofend;

theorem :: INTEGRA8:24
- sin is_differentiable_on REAL
proofend;

theorem Th25: :: INTEGRA8:25
for x being Real holds
( - cos is_differentiable_in x &amp; diff ((- cos),x) = sin . x )
proofend;

theorem Th26: :: INTEGRA8:26
( - cos is_differentiable_on REAL &amp; ( for x being Real st x in REAL holds
diff ((- cos),x) = sin . x ) )
proofend;

theorem Th27: :: INTEGRA8:27
sin `| REAL = cos
proofend;

theorem Th28: :: INTEGRA8:28
cos `| REAL = - sin
proofend;

theorem Th29: :: INTEGRA8:29
(- cos) `| REAL = sin by Th26, FDIFF_1:def_7, SIN_COS:24;

theorem Th30: :: INTEGRA8:30
sinh `| REAL = cosh
proofend;

theorem Th31: :: INTEGRA8:31
cosh `| REAL = sinh
proofend;

theorem Th32: :: INTEGRA8:32
exp_R `| REAL = exp_R
proofend;

theorem Th33: :: INTEGRA8:33
for Z being open Subset of REAL st Z c= dom tan holds
( tan is_differentiable_on Z &amp; ( for x being Real st x in Z holds
(tan `| Z) . x = 1 / ((cos . x) ^2) ) )
proofend;

theorem Th34: :: INTEGRA8:34
for Z being open Subset of REAL st Z c= dom cot holds
( cot is_differentiable_on Z &amp; ( for x being Real st x in Z holds
(cot `| Z) . x = - (1 / ((sin . x) ^2)) ) )
proofend;

theorem :: INTEGRA8:35
for r being Real holds rng (REAL --> r) c= REAL
proofend;

definition
let r be Real;
func Cst r ->  Function of REAL,REAL equals :: INTEGRA8:def 1
REAL --> r;
coherence
 REAL --> r is Function of REAL,REAL ;
end;

:: deftheorem  defines Cst INTEGRA8:def_1_:_
 for r being Real holds Cst r = REAL --> r;

theorem Th36: :: INTEGRA8:36
for a, b being Real
for A being non empty closed_interval Subset of REAL holds chi (A,A) = (Cst 1) | A
proofend;

theorem Th37: :: INTEGRA8:37
for a, b being Real
for A being non empty closed_interval Subset of REAL st A = [.a,b.] holds
( upper_bound A = b &amp; lower_bound A = a )
proofend;

begin

theorem :: INTEGRA8:38
for a, b being Real st a <= b holds
integral ((Cst 1),a,b) = b - a
proofend;

Lm5:  dom sin = REAL
by FUNCT_2:def_1;

Lm6:  dom cos = REAL
by FUNCT_2:def_1;

Lm7:  dom (- sin) = REAL
by FUNCT_2:def_1;

Lm8:  dom exp_R = REAL
by FUNCT_2:def_1;

Lm9:  dom sinh = REAL
by FUNCT_2:def_1;

Lm10:  dom cosh = REAL
by FUNCT_2:def_1;

Lm11:  for A being non empty closed_interval Subset of REAL holds
( cos is_integrable_on A &amp; cos | A is bounded )
proofend;

theorem Th39: :: INTEGRA8:39
for A being non empty closed_interval Subset of REAL holds integral (cos,A) = (sin . (upper_bound A)) - (sin . (lower_bound A))
proofend;

theorem :: INTEGRA8:40
for A being non empty closed_interval Subset of REAL st A = [.0,(PI / 2).] holds
integral (cos,A) = 1
proofend;

theorem :: INTEGRA8:41
for A being non empty closed_interval Subset of REAL st A = [.0,PI.] holds
integral (cos,A) = 0
proofend;

theorem :: INTEGRA8:42
for A being non empty closed_interval Subset of REAL st A = [.0,((PI * 3) / 2).] holds
integral (cos,A) = - 1
proofend;

theorem :: INTEGRA8:43
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * 2).] holds
integral (cos,A) = 0
proofend;

theorem :: INTEGRA8:44
for A being non empty closed_interval Subset of REAL
for n being Element of NAT st A = [.((2 * n) * PI),(((2 * n) + 1) * PI).] holds
integral (cos,A) = 0
proofend;

theorem :: INTEGRA8:45
for A being non empty closed_interval Subset of REAL
for x being Real
for n being Element of NAT st A = [.(x + ((2 * n) * PI)),(x + (((2 * n) + 1) * PI)).] holds
integral (cos,A) = - (2 * (sin x))
proofend;

Lm12:  for A being non empty closed_interval Subset of REAL holds
( - sin is_integrable_on A &amp; (- sin) | A is bounded )
proofend;

theorem Th46: :: INTEGRA8:46
for A being non empty closed_interval Subset of REAL holds integral ((- sin),A) = (cos . (upper_bound A)) - (cos . (lower_bound A))
proofend;

theorem :: INTEGRA8:47
for A being non empty closed_interval Subset of REAL st A = [.0,(PI / 2).] holds
integral ((- sin),A) = - 1
proofend;

theorem :: INTEGRA8:48
for A being non empty closed_interval Subset of REAL st A = [.0,PI.] holds
integral ((- sin),A) = - 2
proofend;

theorem :: INTEGRA8:49
for A being non empty closed_interval Subset of REAL st A = [.0,((PI * 3) / 2).] holds
integral ((- sin),A) = - 1
proofend;

theorem :: INTEGRA8:50
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * 2).] holds
integral ((- sin),A) = 0
proofend;

theorem :: INTEGRA8:51
for A being non empty closed_interval Subset of REAL
for n being Element of NAT st A = [.((2 * n) * PI),(((2 * n) + 1) * PI).] holds
integral ((- sin),A) = - 2
proofend;

theorem :: INTEGRA8:52
for A being non empty closed_interval Subset of REAL
for x being Real
for n being Element of NAT st A = [.(x + ((2 * n) * PI)),(x + (((2 * n) + 1) * PI)).] holds
integral ((- sin),A) = - (2 * (cos x))
proofend;

Lm13:  for A being non empty closed_interval Subset of REAL holds
( exp_R is_integrable_on A &amp; exp_R | A is bounded )
proofend;

theorem Th53: :: INTEGRA8:53
for A being non empty closed_interval Subset of REAL holds integral (exp_R,A) = (exp_R . (upper_bound A)) - (exp_R . (lower_bound A))
proofend;

theorem :: INTEGRA8:54
for A being non empty closed_interval Subset of REAL st A = [.0,1.] holds
integral (exp_R,A) = number_e - 1
proofend;

Lm14:  for A being non empty closed_interval Subset of REAL holds sinh | A is continuous
proofend;

Lm15:  for A being non empty closed_interval Subset of REAL holds
( sinh is_integrable_on A &amp; sinh | A is bounded )
proofend;

theorem Th55: :: INTEGRA8:55
for A being non empty closed_interval Subset of REAL holds integral (sinh,A) = (cosh . (upper_bound A)) - (cosh . (lower_bound A))
proofend;

theorem :: INTEGRA8:56
for A being non empty closed_interval Subset of REAL st A = [.0,1.] holds
integral (sinh,A) = ((number_e - 1) ^2) / (2 * number_e)
proofend;

Lm16:  for A being non empty closed_interval Subset of REAL holds cosh | A is continuous
proofend;

Lm17:  for A being non empty closed_interval Subset of REAL holds
( cosh is_integrable_on A &amp; cosh | A is bounded )
proofend;

theorem Th57: :: INTEGRA8:57
for A being non empty closed_interval Subset of REAL holds integral (cosh,A) = (sinh . (upper_bound A)) - (sinh . (lower_bound A))
proofend;

theorem :: INTEGRA8:58
for A being non empty closed_interval Subset of REAL st A = [.0,1.] holds
integral (cosh,A) = ((number_e ^2) - 1) / (2 * number_e)
proofend;

theorem :: INTEGRA8:59
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL
for Z being open Subset of REAL st A c= Z &amp; dom tan = Z &amp; dom tan = dom f2 &amp; ( for x being Real st x in Z holds
( f2 . x = 1 / ((cos . x) ^2) &amp; cos . x <> 0 ) ) &amp; f2 | A is continuous holds
integral (f2,A) = (tan . (upper_bound A)) - (tan . (lower_bound A))
proofend;

theorem :: INTEGRA8:60
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL
for Z being open Subset of REAL st A c= Z &amp; dom cot = Z &amp; dom cot = dom f2 &amp; ( for x being Real st x in Z holds
( f2 . x = - (1 / ((sin . x) ^2)) &amp; sin . x <> 0 ) ) &amp; f2 | A is continuous holds
integral (f2,A) = (cot . (upper_bound A)) - (cot . (lower_bound A))
proofend;

theorem :: INTEGRA8:61
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL st dom tanh = dom f2 &amp; ( for x being Real st x in REAL holds
f2 . x = 1 / ((cosh . x) ^2) ) &amp; f2 | A is continuous holds
integral (f2,A) = (tanh . (upper_bound A)) - (tanh . (lower_bound A))
proofend;

Lm18:  dom (arcsin `| ].(- 1),1.[) = ].(- 1),1.[
by FDIFF_1:def_7, SIN_COS6:83;

theorem Th62: :: INTEGRA8:62
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL st A c= ].(- 1),1.[ &amp; dom (arcsin `| ].(- 1),1.[) = dom f2 &amp; ( for x being Real holds
( x in ].(- 1),1.[ &amp; f2 . x = 1 / (sqrt (1 - (x ^2))) ) ) &amp; f2 | A is continuous holds
integral (f2,A) = (arcsin . (upper_bound A)) - (arcsin . (lower_bound A))
proofend;

theorem Th63: :: INTEGRA8:63
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL st A c= ].(- 1),1.[ &amp; dom (arccos `| ].(- 1),1.[) = dom f2 &amp; ( for x being Real holds
( x in ].(- 1),1.[ &amp; f2 . x = - (1 / (sqrt (1 - (x ^2)))) ) ) &amp; f2 | A is continuous holds
integral (f2,A) = (arccos . (upper_bound A)) - (arccos . (lower_bound A))
proofend;

theorem :: INTEGRA8:64
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL st A = [.(- ((sqrt 2) / 2)),((sqrt 2) / 2).] &amp; dom (arcsin `| ].(- 1),1.[) = dom f2 &amp; ( for x being Real holds
( x in ].(- 1),1.[ &amp; f2 . x = 1 / (sqrt (1 - (x ^2))) ) ) &amp; f2 | A is continuous holds
integral (f2,A) = PI / 2
proofend;

theorem :: INTEGRA8:65
for f2 being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL st A = [.(- ((sqrt 2) / 2)),((sqrt 2) / 2).] &amp; dom (arccos `| ].(- 1),1.[) = dom f2 &amp; ( for x being Real holds
( x in ].(- 1),1.[ &amp; f2 . x = - (1 / (sqrt (1 - (x ^2)))) ) ) &amp; f2 | A is continuous holds
integral (f2,A) = - (PI / 2)
proofend;

theorem Th66: :: INTEGRA8:66
for f, g being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL
for Z being open Subset of REAL st f is_differentiable_on Z &amp; g is_differentiable_on Z &amp; A c= Z &amp; f `| Z is_integrable_on A &amp; (f `| Z) | A is bounded &amp; g `| Z is_integrable_on A &amp; (g `| Z) | A is bounded holds
integral (((f `| Z) + (g `| Z)),A) = (((f . (upper_bound A)) - (f . (lower_bound A))) + (g . (upper_bound A))) - (g . (lower_bound A))
proofend;

theorem Th67: :: INTEGRA8:67
for f, g being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL
for Z being open Subset of REAL st f is_differentiable_on Z &amp; g is_differentiable_on Z &amp; A c= Z &amp; f `| Z is_integrable_on A &amp; (f `| Z) | A is bounded &amp; g `| Z is_integrable_on A &amp; (g `| Z) | A is bounded holds
integral (((f `| Z) - (g `| Z)),A) = ((f . (upper_bound A)) - (f . (lower_bound A))) - ((g . (upper_bound A)) - (g . (lower_bound A)))
proofend;

theorem Th68: :: INTEGRA8:68
for f being PartFunc of REAL,REAL
for A being non empty closed_interval Subset of REAL
for r being Real
for Z being open Subset of REAL st f is_differentiable_on Z &amp; A c= Z &amp; f `| Z is_integrable_on A &amp; (f `| Z) | A is bounded holds
integral ((r (#) (f `| Z)),A) = (r * (f . (upper_bound A))) - (r * (f . (lower_bound A)))
proofend;

Lm19:  for A being non empty closed_interval Subset of REAL holds
( sin is_integrable_on A &amp; sin | A is bounded )
proofend;

theorem Th69: :: INTEGRA8:69
for A being non empty closed_interval Subset of REAL holds integral ((sin + cos),A) = ((((- cos) . (upper_bound A)) - ((- cos) . (lower_bound A))) + (sin . (upper_bound A))) - (sin . (lower_bound A))
proofend;

theorem :: INTEGRA8:70
for A being non empty closed_interval Subset of REAL st A = [.0,(PI / 2).] holds
integral ((sin + cos),A) = 2
proofend;

theorem :: INTEGRA8:71
for A being non empty closed_interval Subset of REAL st A = [.0,PI.] holds
integral ((sin + cos),A) = 2
proofend;

theorem :: INTEGRA8:72
for A being non empty closed_interval Subset of REAL st A = [.0,((PI * 3) / 2).] holds
integral ((sin + cos),A) = 0
proofend;

theorem :: INTEGRA8:73
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * 2).] holds
integral ((sin + cos),A) = 0
proofend;

theorem :: INTEGRA8:74
for A being non empty closed_interval Subset of REAL
for n being Element of NAT st A = [.((2 * n) * PI),(((2 * n) + 1) * PI).] holds
integral ((sin + cos),A) = 2
proofend;

theorem :: INTEGRA8:75
for A being non empty closed_interval Subset of REAL
for x being Real
for n being Element of NAT st A = [.(x + ((2 * n) * PI)),(x + (((2 * n) + 1) * PI)).] holds
integral ((sin + cos),A) = (2 * (cos x)) - (2 * (sin x))
proofend;

theorem Th76: :: INTEGRA8:76
for A being non empty closed_interval Subset of REAL holds integral ((sinh + cosh),A) = (((cosh . (upper_bound A)) - (cosh . (lower_bound A))) + (sinh . (upper_bound A))) - (sinh . (lower_bound A))
proofend;

theorem :: INTEGRA8:77
for A being non empty closed_interval Subset of REAL st A = [.0,1.] holds
integral ((sinh + cosh),A) = number_e - 1
proofend;

theorem Th78: :: INTEGRA8:78
for A being non empty closed_interval Subset of REAL holds integral ((sin - cos),A) = (((- cos) . (upper_bound A)) - ((- cos) . (lower_bound A))) - ((sin . (upper_bound A)) - (sin . (lower_bound A)))
proofend;

theorem :: INTEGRA8:79
for A being non empty closed_interval Subset of REAL st A = [.0,(PI / 2).] holds
integral ((sin - cos),A) = 0
proofend;

theorem :: INTEGRA8:80
for A being non empty closed_interval Subset of REAL st A = [.0,PI.] holds
integral ((sin - cos),A) = 2
proofend;

theorem :: INTEGRA8:81
for A being non empty closed_interval Subset of REAL st A = [.0,((PI * 3) / 2).] holds
integral ((sin - cos),A) = 2
proofend;

theorem :: INTEGRA8:82
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * 2).] holds
integral ((sin - cos),A) = 0
proofend;

theorem :: INTEGRA8:83
for A being non empty closed_interval Subset of REAL
for n being Element of NAT st A = [.((2 * n) * PI),(((2 * n) + 1) * PI).] holds
integral ((sin - cos),A) = 2
proofend;

theorem :: INTEGRA8:84
for A being non empty closed_interval Subset of REAL
for x being Real
for n being Element of NAT st A = [.(x + ((2 * n) * PI)),(x + (((2 * n) + 1) * PI)).] holds
integral ((sin - cos),A) = (2 * (cos x)) + (2 * (sin x))
proofend;

theorem :: INTEGRA8:85
for A being non empty closed_interval Subset of REAL
for r being Real holds integral ((r (#) sin),A) = (r * ((- cos) . (upper_bound A))) - (r * ((- cos) . (lower_bound A)))
proofend;

theorem :: INTEGRA8:86
for A being non empty closed_interval Subset of REAL
for r being Real holds integral ((r (#) cos),A) = (r * (sin . (upper_bound A))) - (r * (sin . (lower_bound A)))
proofend;

theorem :: INTEGRA8:87
for A being non empty closed_interval Subset of REAL
for r being Real holds integral ((r (#) sinh),A) = (r * (cosh . (upper_bound A))) - (r * (cosh . (lower_bound A)))
proofend;

theorem :: INTEGRA8:88
for A being non empty closed_interval Subset of REAL
for r being Real holds integral ((r (#) cosh),A) = (r * (sinh . (upper_bound A))) - (r * (sinh . (lower_bound A)))
proofend;

theorem :: INTEGRA8:89
for A being non empty closed_interval Subset of REAL
for r being Real holds integral ((r (#) exp_R),A) = (r * (exp_R . (upper_bound A))) - (r * (exp_R . (lower_bound A)))
proofend;

theorem Th90: :: INTEGRA8:90
for A being non empty closed_interval Subset of REAL holds integral ((sin (#) cos),A) = (1 / 2) * (((cos . (lower_bound A)) * (cos . (lower_bound A))) - ((cos . (upper_bound A)) * (cos . (upper_bound A))))
proofend;

theorem :: INTEGRA8:91
for A being non empty closed_interval Subset of REAL st A = [.0,(PI / 2).] holds
integral ((sin (#) cos),A) = 1 / 2
proofend;

theorem :: INTEGRA8:92
for A being non empty closed_interval Subset of REAL st A = [.0,PI.] holds
integral ((sin (#) cos),A) = 0
proofend;

theorem :: INTEGRA8:93
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * (3 / 2)).] holds
integral ((sin (#) cos),A) = 1 / 2
proofend;

theorem :: INTEGRA8:94
for A being non empty closed_interval Subset of REAL st A = [.0,(PI * 2).] holds
integral ((sin (#) cos),A) = 0
proofend;

theorem :: INTEGRA8:95
for A being non empty closed_interval Subset of REAL
for n being Element of NAT st A = [.((2 * n) * PI),(((2 * n) + 1) * PI).] holds
integral ((sin (#) cos),A) = 0
proofend;

theorem :: INTEGRA8:96
for A being non empty closed_interval Subset of REAL
for x being Real
for n being Element of NAT st A = [.(x + ((2 * n) * PI)),(x + (((2 * n) + 1) * PI)).] holds
integral ((sin (#) cos),A) = 0
proofend;

Lm20:  for A being non empty closed_interval Subset of REAL holds
( cos (#) cos is_integrable_on A &amp; (cos (#) cos) | A is bounded )
proofend;

theorem :: INTEGRA8:97
for A being non empty closed_interval Subset of REAL holds integral ((sin (#) sin),A) = (((cos . (lower_bound A)) * (sin . (lower_bound A))) - ((cos . (upper_bound A)) * (sin . (upper_bound A)))) + (integral ((cos (#) cos),A))
proofend;

theorem :: INTEGRA8:98
for A being non empty closed_interval Subset of REAL holds integral ((sinh (#) sinh),A) = (((cosh . (upper_bound A)) * (sinh . (upper_bound A))) - ((cosh . (lower_bound A)) * (sinh . (lower_bound A)))) - (integral ((cosh (#) cosh),A))
proofend;

theorem :: INTEGRA8:99
for A being non empty closed_interval Subset of REAL holds integral ((sinh (#) cosh),A) = (1 / 2) * (((cosh . (upper_bound A)) * (cosh . (upper_bound A))) - ((cosh . (lower_bound A)) * (cosh . (lower_bound A))))
proofend;

theorem :: INTEGRA8:100
for A being non empty closed_interval Subset of REAL holds integral ((exp_R (#) exp_R),A) = (1 / 2) * (((exp_R . (upper_bound A)) ^2) - ((exp_R . (lower_bound A)) ^2))
proofend;

Lm21:  for A being non empty closed_interval Subset of REAL holds
( exp_R (#) (sin + cos) is_integrable_on A &amp; (exp_R (#) (sin + cos)) | A is bounded )
proofend;

Lm22:  for A being non empty closed_interval Subset of REAL holds
( exp_R (#) (cos - sin) is_integrable_on A &amp; (exp_R (#) (cos - sin)) | A is bounded )
proofend;

theorem :: INTEGRA8:101
for A being non empty closed_interval Subset of REAL holds integral ((exp_R (#) (sin + cos)),A) = ((exp_R (#) sin) . (upper_bound A)) - ((exp_R (#) sin) . (lower_bound A))
proofend;

theorem :: INTEGRA8:102
for A being non empty closed_interval Subset of REAL holds integral ((exp_R (#) (cos - sin)),A) = ((exp_R (#) cos) . (upper_bound A)) - ((exp_R (#) cos) . (lower_bound A))
proofend;