USING: accessors arrays combinators kernel ;

IN: math.intervals

: interval-op ( i1 i2 quot -- i3 nan? )
{
[ [ from>> ] [ from>> ] [ ] tri* (interval-op) ]
[ [ to>> ] [ from>> ] [ ] tri* (interval-op) ]
[ [ to>> ] [ to>> ] [ ] tri* (interval-op) ]
[ [ from>> ] [ to>> ] [ ] tri* (interval-op) ]
} 3cleave 4array points>interval ; inline