But x isn’t x + 5. If anything, it should be “x becomes x + 5”.
Ok. How about
Set x to x + 5
That’s pretty much COBOL syntax: https://www.ibm.com/docs/en/debug-for-zos/17.0.x?topic=comma...
Except that COBOL doesn’t allow an arithmetic expression there, so you have to write
COMPUTE X = X + 5.
x is 5
x is x + 5