@+(value, value) ; listable
@+ is the prefix form of the infix binary operator
@+(x, y) ≡ x + y
The functional form of the operator is useful as an argument of a
high-order function as in
@reduce(@+, v) which sums up all the
elements of the tab
The addition of an
int and a
float returns a
The addition of two
string corresponds to the concatenation of the arguments.
The addition of a
string and any other value convert this value into its
string representation before the concatenation.