+ is a standard operator that adds (i.e. Sums) two values.

SYNTAX:

Exp + Exp
Where:
Exp is an Expression

EXAMPLES:

1 + 2 = 3
V1 + V4011 = Adds Variable 1's value to Variable 4011's value
C1 + V4011 = Adds Variable 1's value (and treats blank value as zero) to Variable 4011's value.