When the expressions to be combined are small, write them all on one line.
F | G | H
When the combined expressions are large enough to take up a full line, write one expression
per line, with each subsequent expression aligned with the first and preceded by
Indent the first expression to improve readability.
long expression | long expression | long expression
A sequence of parallel expressions often form the left hand side of a sequential combinator. Since the sequential combinator has higher precedence, use parentheses to group the combined parallel expressions together.
( expression | expression ) >x> another expression