func(circs,{
  sub({
     let(x1,elem([x],1))
    :let(x2,elem([y],1))
    :let(x3,elem([z],1))
    :let(y1,elem([x],2))
    :let(y2,elem([y],2))
    :let(y3,elem([z],2))
    :let(alpha,(([x2])^2)-(([x1])^2)+(([y2])^2)-(([y1])^2))
    :let(delta,(([x3])^2)-(([x1])^2)+(([y3])^2)-(([y1])^2))
    :let(beta,   -2*([x2])+2*([x1]))
    :let(gamma,   2*([y1])-2*([y2]))
    :let(epsilon,-2*([x3])+2*([x1]))
    :let(rho,     2*([y1])-2*([y3]))
    :let(machine,0.0001):
    :`Some division-by-zero prevention...'
    :let(beta,   iff(greater([machine],abs([beta])),
                   {[beta]+[machine]},{[beta]}))
    :let(gamma,  iff(greater([machine],abs([gamma])),
                   {[gamma]+[machine]},{[gamma]}))
    :let(epsilon,iff(greater([machine],abs([epsilon])),
                   {[epsilon]+[machine]},{[epsilon]}))
    :let(rho,    iff(greater([machine],abs([rho])),
                   {[rho]+[machine]},{[rho]}))
    :let(k,([alpha]/[beta]-[delta]/[epsilon])
          /([rho]/[epsilon]-[gamma]/[beta]))
    :let(h,([alpha]/[gamma]-[delta]/[rho])
          /([epsilon]/[rho]-[beta]/[gamma]))
    :let(rad,sqrt(([x1]-[h])^2+([y1]-[k])^2))
    :let(result,<[h],[k],[rad]>)
    :print_[result]
  })
})(<4,1>,<-3,7>,<5,-3>)