HP 40g hp 39g+ (39g & 40g)_mastering the hp 39g+_English_E_F2224-90010.pdf - Page 233

PROGRAMMING COMMANDS All programming commands can by typed in by hand but, as with the MATH commands, can also be obtained from a menu. Press SHIFT CMDS to display this. In this section I will only be covering those commands which I have used regularly and so regard as important. These may not be the same as the ones you regard as important. If so, consult the manual. The Aplet commands These control aspects of the aplet. CHECK n, UNCHECK n These commands put or remove a check next to the equation whose number is given by n. An interesting bug is actually quite useful: if you UNCHECK 0 then all equations are unchecked instead of only equation 0. Unfortunately the same is not true for the CHECK command. As they say in the trade: "It's not a bug, it's a feature!". SELECT This is used to set the active aplet if necessary. If the name has spaces in it then it must be enclosed in quotes. This is not usually required as the program will normally be called by the active aplet anyway. I have only used it with 'stand-alone' programs not attached to an aplet so that they can temporarily 'borrow' abilities belonging to an aplet. However, it could also be used to create an aplet that had two 'parents' if you required it to inherit abilities from both. You could then swap from one parent to the other using this command. This could be quite cumbersome but might add some powerful features. 233