A longsety is a sequence of zero or more long bold
tags. The term follows the fashion of the Revised Report, where the
suffix -ety means “or empty”.
The Algol 68 modes int, real, compl,
bits and bytes can be prefixed with any number
of long tag words. The effect of each long is
to double the precision of the mode.
At some point, however, a “saturation” point is reached where the
addition of extra long has no further effect on the mode.
Where that point resides is up to the particular implementation.
For example, if the precision of int is four bytes or
32-bit, the precision of long int is 64-bit, and the
precision of long long int is 128-bit.
Simplified [RR 1.2.1.E]:
E) LONGSETY :: long LONGSETY ; EMPTY.