In Algol 68 the go-on symbol, represented by a semicolon ;,
denotes serial elaboration, like in the serial clause (a;b;c).
Conversely, the comma symbol , denotes collateral elaboration,
like in the collateral clause (a,b,c).
This convention is followed in the syntax of calls to procedures that
accept parameters, in which the units conforming the actual parameters
are separated by commas, like in foo(a,b,c). The units a, b,
and c are elaborated collaterally.
The original unrevised language supported a variant of procedure calls
in which the actual parameters were separated by go-on symbols
instead, such as in foo(a;b;c). In this variant, the units
were elaborated sequentially rather than collaterally.
A gomma was the term to refer to either a go-on symbol or a comma. Gommas were removed from the language in its revised version.