Assigns EXPR to VAR. The LET part of the statement is optional, if it is purely an assignment, i.e., A = 9 is equivalent to LET A = 9. LET is obligatory when using the IF..THEN construct, if you want to assign a value to a variable. For instance, IF A = B THEN A = 1000 will cause the program to perform a GOTO to the line specified by A. To achieve the required result, use the LET statement, i.e., IF A = B THEN LET A = 1000.
Program Example.
00100 LET A = 10
00110 IF A = 10 THEN LET A = 20
00120 PRINT A
00130 A = 30
00140 PRINT A
00150 END