Main functions.

  The main functions of the ALGB library are assigned to keys in user mode. If you don't see the word USER in the status area (or with JAVA if you see NORM in the status area), you should go in USER mode: press once or twice the left shift key followed by the key.

The redefined keys are most of the time preceded by the and right-shift keys. For example, the add addition function of ALGB is obtained in USER mode by hiting threes keys: , , .

The same method applies for other operations. The +, -, *, /, y^x, , , , 1/x, keys are redefined (after and ) as add, SUBT, MULT, DIV1, POWER, SQRT, CHS, FDER, FINTG, MAD. The seven first commands extend the usual HP commands to all ALGB data types. The FDER command does differentiation with respect to the main variable (contained in 'VX': usually 'X'), you don't have to put 'X' on the stack. The FINTG tries to integrate with respect to the main variable between and the main variable. It extends the built-in symbolic integration to rational fractions (you must however set the flag 13 to be able to integrate all rational fractions). The MAD command is not an inverse function, it is used mainly for matrices to compute eigenvalues. However the inverse is returned at level 3, that's why I assigned this key to MAD.

The other -right shift-redefined keys are:

• the 9 key calls EXPA which extends the EXPAN function of the HP. It fully expands expressions in one pass.
• the 6 keys is redefined as COLC which tries to factorize an expression (this has a similar effect to the COLCT instruction).
• the 3 keys lets you switch from numeric to symbolic array representaion of an array. The space key switches on or off the user flag 13.
• the 7 key finds the roots and poles of a rational fraction (function FROOTS),
• the 4 key evaluates an object at stack level 1 and returns an approximation of the time needed (tEVAL function).
• the 1 key calls rref to reduce to echelon form a symbolic or numeric array.
• The 5 key calls the EXEC function which is used to execute something (e.g replace a variable by a value, or execute a program) on an object

Let's finish this section by two redefined keys which are not -right shifted:

• On SX models, the Q and NUM keys (not alpha shifted) are redefined to handle matrices. They toggle user flags 12, 14 and 15 (XNUM to clear and XQ to set).
• On a G/GX models, use - -Q or NUM (not shifted).