fcn mapRange([(a1,a2)], [(b1,b2)], s) // a1a2 is List(a1,a2)
   { b1 + ((s - a1) * (b2 - b1) / (a2 - a1)) }

r1:=T(0.0, 10.0); r2:=T(-1.0, 0.0);
foreach s in ([0.0 .. 10]){
   "%2d maps to %5.2f".fmt(s,mapRange(r1,r2, s)).println();
}