1. An electronic calculator comprising: keyboard input means for entering alphameric information, including lines of algebraic statements, into the calculator; memory means for storing a program of lines of algebraic statements previously entered into the calculator; processing means, coupled to said keyboard input means and memory means, for processing lines of algebraic statements entered into the calculator and stored in said memory means to perform selected functions; and output means, coupled to said processing means, for providing a visual indication of selected functions performed by said processing means; said keyboard input means including a plurality of keys for specifying one of a plurality of boolean flag variables to be entered as part of an algebraic statement, and a plurality of flag variable control keys for entering flag statements, each flag statement specifying one of a clearing, setting, and testing function in connection with a designated one of said plurality of boolean flag variables, said keyboard means including a display control key operative in combination with selected ones of said plurality of keys specifying one of said plurality of boolean flag variables for entering a flag display statement to initiate visual display on said output means of the state of the specified boolean flag variable.