NaN (not a number) is a numeric data type value representing an undefined or unrepresentable value.
These values result from operations which have undefined numerical results.
NaN is not the same as infinity.
1 program NotANumber(input, output, stderr); 2 begin 3 // writes 'Nan' (with spacing) on its own line 4 writeLn(0/0); 5 end.
NaN exists only in the context of floating point number calculations:
0 div 0 (integer division) is not allowed, though.