**Defined in theory: Kif-numbers****Source code: kif-numbers.lisp****Also defined in:**Physical-quantities, Basic-matrix-algebra, Tensor-quantities

**Documentation:**If $tau$ and $tau_1$, ..., $tau_n$ denote numbers, then the term {tt (- $tau$ $tau_1 ... tau_n$)} denotes the difference between the

number denoted by $tau$ and the numbers denoted by $tau_1$ through $tau_n$. An exception occurs when $n=0$, in which case the term denotes the negation of the number denoted by $tau$.

(Undefined (Arity -))