*repeats the group contents below any number of times:
?matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
+the literal + (4310 / 538 / 2B16)
\d*a digit, repeated any number of times
\.?optionally matches the literal . (4610 / 568 / 2E16)
\d+a digit, repeated at least once
\/the literal / (4710 / 578 / 2F16)
*the literal * (4210 / 528 / 2A16)
+the literal + (4310 / 538 / 2B16)
-the literal - (4510 / 558 / 2D16)