Rules
What is not accepted
Names and forms that look right and are not.
ʝ is the imaginary unit. i and j are ordinary names. There is no function named log, and no getconst, atomicweight, molecularweight, gaussel, or crandom. A degree symbol is not an operator. A string is not a value. The only quoted text is a plot label, and doubling a quote does not escape it. ; starts a new matrix row. It does not end a statement. A loop on the sheet, outside a function, is rejected.
Errors you will see
24 y := x the := value is not already known
28 a loop outside a function loops are only allowed inside a function
30 0/0, 0^0, a bad factorial calculation error
41 sin(x) := x a built-in name used as a function
43 ln(0), a bad index invalid function argument
1006 minimize(-a, a) no finite minimum
1013 maximize(a, a) no finite maximum
1011 a name still unknown the message mentions roundoff
1014 1 = 0 the equations cannot be solved
The number is ErrorCode. A quote that is not a plot label stops the process instead of returning one of these.