Scilab Function
Last update : April 1993

trisolve - symbolic linear system solver

### Calling Sequence

  `[x [,sexp]] = trisolve(A,b [,sexp])`

### Parameters

- `A,b`: matrices of strings

### Description

symbolically solves `A*x =b` , `A` being assumed to be upper triangular.

`sexp` is a vector of common subexpressions in `A, b, x`.

### Examples

    A=['x','y';'0','z'];b=['0';'1'];
    w=trisolve(A,b)
    x=5;y=2;z=4;
    evstr(w)
    inv(evstr(A))*evstr(b)

### See Also

`trianfml`, `solve`,

### Author

F.D, S.S