Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
Function: display (<expr_1>, <expr_2>, ...) Displays equations whose left side is <expr_i> unevaluated, and whose right side is the value of the expression centered on the line. This function is useful in blocks and for statements in order to have intermediate results displayed. The arguments to display are usually atoms, subscripted variables, or function calls. See also disp.

(%i1) display(B[1,2]);
2
B = X - X
1, 2
(%o1) done There are also some inexact matches for display. Try ?? display to see them.
(%o1) true (%i2)