symbolic mathematical programming....?

is it possible to do symbolic mathematical programming in the following way:

for example

let a=b+c

let d=a+c

let b=x

let c=y

print "d"

let x=1

let y=2

the evaluate "d"

output...d=b+2c; d=5

what if a,b,c=an integral Expression or a differential equations or a partial differential equations, a curl or a div...

a curl is actually the surface area of an integral

a div is actually the gradient of a partial differential equations...

what if u don't add or substract a, b, c but multiple or divide them also.

u evaluate each expressions and simplifies them and print the final answer. each expression

can be evaluate by maple 15. all u have to do is add, substract, multiply and divided them and then use the evaluate and display inline function to simplify the expressions........

for example:

let b=integral x^2

let c=differentiate (3x^5+2x+1)

let a=b+c

let d=a+c

print "d"

let x=1......

evaluate "d"

output....d=x^3/3+c1+2(15x^4+2x)=30x^4+x^3/3+4x+c1, d=34.33+c1......

u can further solve the equation by inputting the boundary values...say if when x=0, d=34.33, so c1=0.

would that gives u a simple symbolic mathematical programming method....?