<cl> pi ;; CommonLispに組み込みです. 3.141592653589793d0 <cl> (= pi 3.141592653589793d0) T <cl> (= pi 3.141592653589793) NIL
<cl> (asin 1) 1.5707964 ;; 倍精度ではない. <cl> (= (asin 1) (/ pi 2)) ;; 等しくない. NIL <cl> (asin 1.0d0) 1.5707963267948966d0 <cl> (= (asin 1.0d0) (/ pi 2)) ;; これで等しい T <cl> (sin (/ pi 2)) 1.0d0 <cl> (asin (sin (/ pi 2))) 1.5707963267948966d0 <cl> (= (/ pi 2) (asin (sin (/ pi 2)))) T <cl> (= (atan (sin (/ pi 2)) (cos (/ pi 2))) (/ pi 2)) 1.5707963267948966d0 <cl> (= (atan (sin (/ pi 2)) (cos (/ pi 2))) (/ pi 2)) T <cl> (eq (atan (sin (/ pi 2)) (cos (/ pi 2))) (/ pi 2)) NIL