Englishfor English speakers
semigroup
noun
—
set for which a closed associative binary operation is defined
of
Preposition
—
Made using.
It is a house of cards.
operator
Noun
—
An operator is a person who operates something.
Jo is the operator of the tractor.
—
An operator is a person who works on making connections for people over the telephone.
The operator was struggling to keep the line connected.