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