Basic opérations on dimensions

Hello

!It seems there is bug in Draftsigth (French version V1R3)

When i do a substraction (minus sign of the numerical keyboard) to fix the length of an entity.

For example i draw a line of any length and i apply the intelligent command to measure its dimension length (for example : 1165.4)

Using the command panel i type "MODIFLONG

"System  : "Specify entity for length"
User    : "TO"
System  : "Specify total length"
User    : "1165.4-100"
System  : "Setting length to 1265.4"
User    : "Esc"
The lengt of the line is set to 1265.4 instead of 1065.4

Doing the same process with an addition (+) or a division (/), the result is correct.
Unfortunaly, the result is not delivered when i do a multiplication (*)

Could you say to me if these kinds of operations are not supported ?

Best regards for your support !