Overview.

Erable is a computer algebra system for the HP48. The main features are simplifications (including complexes and square roots), integration, first order differential equations, partial fraction decomposition, Laplace and inverse Laplace transform, limits, Taylor and asymptotic series, row reduction to echelon form of matrices, linear system (including over and underdetermined), eigenvalues and eigenvectors, quadratic forms, permutations, variables substitution, ... With Erable you will be able to solve most problems solved by a TI92 and some problems which are not solved by a TI92: some integrals (the Risch algorithm is not implemented in the TI92), some Taylor series, arithmetic, diagonalization of matrices, change of variables,...
If you have both alg48 and Erable, then you have the most complete computer algebra system currently available on a calculator (HP, TI and CASIO).

Examples:

$$\begin{eqnarray*}\frac{1+\sqrt{2}}{1+2\sqrt{2}} &\mbox{EXPA} & \frac{3}{7}+\frac... ...\ 0 & -2+a+a^2 & 0 \\ 0 & 0 & 2-a-a^2 \end{array}\right)\\ \end{eqnarray*}$$

Examples not solved natively by a TI92:

$$\begin{eqnarray*}\hfill \sin(x)/(e^x-1), x, 4& \mbox{SERIES} & 1-\frac{1}{2} x-\... ...box{JORDAN} & \mbox{Char :1:} (1,0); \mbox{Eigen :1:} (-1,-1)\\ \end{eqnarray*}$$