Question: ODE Test Fails for Solution

I’m trying to verify a solution given in the form from  using Maple's odeTest. Even though the paper claims the solution satisfies the ODE, Maple does not simplify the result to zero. Could someone explain why the test fails or suggest the correct way to verify it in Maple?

> 

restart

> 

with(PDEtools)

> 

with(LinearAlgebra)

> 

with(Physics)

> 

with(SolveTools)

> 

undeclare(prime)

`There is no more prime differentiation variable; all derivatives will be displayed as indexed functions`

(1)
> 

_local(gamma)

Warning, A new binding for the name `gamma` has been created. The global instance of this name is still accessible using the :- prefix, :-`gamma`.  See ?protect for details.

 
> 

declare(u(x, t)); declare(U(xi)); declare(u(x, y, z, t)); declare(Q(xi)); declare(V(xi))

u(x, t)*`will now be displayed as`*u

 

U(xi)*`will now be displayed as`*U

 

u(x, y, z, t)*`will now be displayed as`*u

 

Q(xi)*`will now be displayed as`*Q

 

V(xi)*`will now be displayed as`*V

(2)
> 

NULL

> 

ode := diff(G(xi), xi) = G(xi)*sqrt(A+B*G(xi)^2)

diff(G(xi), xi) = G(xi)*(A+B*G(xi)^2)^(1/2)

(3)
> 

S1 := G(xi) = -sqrt(A/B)*csch(sqrt(A)*(xi+xi[0]))

G(xi) = -(A/B)^(1/2)*csch(A^(1/2)*(xi+xi[0]))

(4)
> 

res := simplify(odetest(S1, ode))

(A/B)^(1/2)*csch(A^(1/2)*(xi+xi[0]))*(A^(1/2)*coth(A^(1/2)*(xi+xi[0]))+(A*coth(A^(1/2)*(xi+xi[0]))^2)^(1/2))

(5)
> 

S2 := G(xi) = sqrt(-A/B)*sec(sqrt(-A)*(xi+xi[0]))

G(xi) = (-A/B)^(1/2)*sec((-A)^(1/2)*(xi+xi[0]))

(6)
> 

res := simplify(odetest(S2, ode))

(-A/B)^(1/2)*sec((-A)^(1/2)*(xi+xi[0]))*((-A)^(1/2)*tan((-A)^(1/2)*(xi+xi[0]))-(-A*tan((-A)^(1/2)*(xi+xi[0]))^2)^(1/2))

(7)
> 

S3 := G(xi) = sqrt(-A/B)*sech(sqrt(A)*(xi+xi[0]))

G(xi) = (-A/B)^(1/2)*sech(A^(1/2)*(xi+xi[0]))

(8)
> 

res := simplify(odetest(S3, ode))

(-A^(1/2)*tanh(A^(1/2)*(xi+xi[0]))-(A*tanh(A^(1/2)*(xi+xi[0]))^2)^(1/2))*(-A/B)^(1/2)*sech(A^(1/2)*(xi+xi[0]))

(9)
> 

S4 := G(xi) = sqrt(-A/B)*csc(sqrt(-A)*(xi+xi[0]))

G(xi) = (-A/B)^(1/2)*csc((-A)^(1/2)*(xi+xi[0]))

(10)
> 

res := simplify(odetest(S4, ode))

(-(-A)^(1/2)*cot((-A)^(1/2)*(xi+xi[0]))-(-A*cot((-A)^(1/2)*(xi+xi[0]))^2)^(1/2))*(-A/B)^(1/2)*csc((-A)^(1/2)*(xi+xi[0]))

(11)
> 

S5 := G(xi) = cos(sqrt(-A)*(xi+xi[0]))+sin(sqrt(-A)*(xi+xi[0]))

G(xi) = cos((-A)^(1/2)*(xi+xi[0]))+sin((-A)^(1/2)*(xi+xi[0]))

(12)
> 

res := simplify(odetest(S5, ode))

(cos((-A)^(1/2)*(xi+xi[0]))-sin((-A)^(1/2)*(xi+xi[0])))*(-A)^(1/2)+(B*sin(2*(-A)^(1/2)*(xi+xi[0]))+A+B)^(1/2)*(-cos((-A)^(1/2)*(xi+xi[0]))-sin((-A)^(1/2)*(xi+xi[0])))

(13)
> 

S6 := G(xi) = 1/(sqrt(B)*(xi+xi[0]))

G(xi) = 1/(B^(1/2)*(xi+xi[0]))

(14)
> 

odetest(S6, subs(A = 0, ode))

-csgn(1/(xi+xi[0]))/(B^(1/2)*(xi+xi[0])^2)-1/(B^(1/2)*(xi+xi[0])^2)

(15)
> 

S7 := G(xi) = 1/(sqrt(-B)*(xi+xi[0]))

G(xi) = 1/((-B)^(1/2)*(xi+xi[0]))

(16)
> 

odetest(S7, subs(A = 0, ode))

-(-1/(xi+xi[0])^2)^(1/2)*xi[0]/((-B)^(1/2)*(xi+xi[0])^2)-(-1/(xi+xi[0])^2)^(1/2)*xi/((-B)^(1/2)*(xi+xi[0])^2)-1/((-B)^(1/2)*(xi+xi[0])^2)

(17)
> 

ode2 := diff(G(xi), xi) = A+B*G(xi)^2

diff(G(xi), xi) = A+B*G(xi)^2

(18)
> 

S8 := G(xi) = sgn(A)*sqrt(A/B)*tan(sqrt(A*B)*(xi+xi[0]))

G(xi) = sgn(A)*(A/B)^(1/2)*tan((A*B)^(1/2)*(xi+xi[0]))

(19)
> 

res := simplify(odetest(S8, ode2))

(sgn(A)*(A*B)^(1/2)*(tan((A*B)^(1/2)*xi[0])^2+1)*(tan((A*B)^(1/2)*xi)^2+1)*(A/B)^(1/2)-A*((tan((A*B)^(1/2)*xi)+tan((A*B)^(1/2)*xi[0]))^2*sgn(A)^2+(tan((A*B)^(1/2)*xi[0])*tan((A*B)^(1/2)*xi)-1)^2))/(tan((A*B)^(1/2)*xi[0])*tan((A*B)^(1/2)*xi)-1)^2

(20)
> 

NULL

> 

S9 := G(xi) = -sgn(A)*sqrt(A/B)*cot(sqrt(A*B)*(xi+xi[0]))

G(xi) = -sgn(A)*(A/B)^(1/2)*cot((A*B)^(1/2)*(xi+xi[0]))

(21)
> 

res := simplify(odetest(S9, ode2))

(sgn(A)*(A*B)^(1/2)*(cot((A*B)^(1/2)*xi[0])^2+1)*(cot((A*B)^(1/2)*xi)^2+1)*(A/B)^(1/2)-A*((cot((A*B)^(1/2)*xi[0])*cot((A*B)^(1/2)*xi)-1)^2*sgn(A)^2+(cot((A*B)^(1/2)*xi[0])+cot((A*B)^(1/2)*xi))^2))/(cot((A*B)^(1/2)*xi[0])+cot((A*B)^(1/2)*xi))^2

(22)
> 

NULL

> 

S9 := G(xi) = sgn(A)*sqrt(-A/B)*tanh(sqrt(-A*B)*(xi+xi[0]))

G(xi) = sgn(A)*(-A/B)^(1/2)*tanh((-A*B)^(1/2)*(xi+xi[0]))

(23)
> 

res := simplify(odetest(S9, ode2))

(A*(sgn(A)^2-1)*cosh(2*(-A*B)^(1/2)*(xi+xi[0]))-sgn(A)^2*A+2*sgn(A)*(-A/B)^(1/2)*(-A*B)^(1/2)-A)/(1+cosh(2*(-A*B)^(1/2)*(xi+xi[0])))

(24)
> 

NULL

> 

S10 := G(xi) = sgn(A)*sqrt(-A/B)*coth(sqrt(-A*B)*(xi+xi[0]))

G(xi) = sgn(A)*(-A/B)^(1/2)*coth((-A*B)^(1/2)*(xi+xi[0]))

(25)
> 

odetest(S10, ode2)

(sgn(A)^2*A*cosh(2*(-A*B)^(1/2)*(xi+xi[0]))+sgn(A)^2*A-2*sgn(A)*(-A/B)^(1/2)*(-A*B)^(1/2)-A*cosh(2*(-A*B)^(1/2)*(xi+xi[0]))+A)/(-1+cosh(2*(-A*B)^(1/2)*(xi+xi[0])))

(26)
> 

NULL

> 

S11 := G(xi) = -1/(B*(xi+xi[0]))

G(xi) = -1/(B*(xi+xi[0]))

(27)
> 

odetest(S11, subs(A = 0, ode2))

0

(28)
> 

S12 := G(xi) = A*(xi+xi[0])

G(xi) = A*(xi+xi[0])

(29)
> 

odetest(S12, subs(B = 0, ode2))

0

(30)

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