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 $tau$.
and also:
The - function is also defined for matrices, where it means the difference between two matrices (in the binary case) or additive inverse in the unary case.
(=> (Matrix ?A) (<=> (- ?A ?C) (And (Matrix ?C) (Forall (?I ?J) (=> (Defined (Value ?C ?I ?J)) (= (Value ?C ?I ?J) (- (Value ?A ?I ?J)))))))) (=> (And (Matrix ?A) (Matrix ?B) (= (Row-Dimension ?A) (Row-Dimension ?B)) (= (Column-Dimension ?A) (Column-Dimension ?B))) (<=> (- ?A ?B ?C) (And (Matrix ?C) (= (Row-Dimension ?A) (Row-Dimension ?C)) (= (Column-Dimension ?A) (Column-Dimension ?C)) (Forall (?I ?J) (=> (Defined (Value ?C ?I ?J)) (= (Value ?C ?I ?J) (- (Value ?A ?I ?J) (Value ?B ?I ?J))))))))
(Undefined (Arity -)) (Undefined (Arity -)) (Undefined (Arity -)) (Undefined (Arity -))
(=> (Matrix ?A) (<=> (- ?A ?C) (And (Matrix ?C) (Forall (?I ?J) (=> (Defined (Value ?C ?I ?J)) (= (Value ?C ?I ?J) (- (Value ?A ?I ?J)))))))) (=> (And (Matrix ?A) (Matrix ?B) (= (Row-Dimension ?A) (Row-Dimension ?B)) (= (Column-Dimension ?A) (Column-Dimension ?B))) (<=> (- ?A ?B ?C) (And (Matrix ?C) (= (Row-Dimension ?A) (Row-Dimension ?C)) (= (Column-Dimension ?A) (Column-Dimension ?C)) (Forall (?I ?J) (=> (Defined (Value ?C ?I ?J)) (= (Value ?C ?I ?J) (- (Value ?A ?I ?J) (Value ?B ?I ?J)))))))) (=> (= (Matrix-Less-Row-And-Column ?A ?I ?J) ?B) (= (Column-Dimension ?B) (- (Column-Dimension ?A) 1))) (=> (= (Matrix-Less-Row-And-Column ?A ?I ?J) ?B) (= (Row-Dimension ?B) (- (Row-Dimension ?A) 1))) (=> (= (Matrix-Less-Row ?A ?I) ?B) (= (Row-Dimension ?B) (- (Row-Dimension ?A) 1))) (=> (= (Matrix-Less-Column ?A ?I) ?B) (= (Column-Dimension ?B) (- (Column-Dimension ?A) 1)))