This is a representation of the formula j=2i+3. Multiplication is represented by an asterisk (*) and addition by a plus sign (+). The value stored with the name i is used in the calculation. The result of the expression is then assigned (=) to the store with name j.
You can also use a minus sign (-), an oblique (/) for divide and a double asterisk for raising to a power but (for INTEGERs) division yields the whole number part of the result (truncated towards zero). The standard mathematical rules of precedence apply whilst brackets can be used to change this order.
Constants (like the 3 used here) can appear within an expression. INTEGER constants may be signed but only the digits 0 to 9 should be used (do not include a decimal point).