Example:

Falsifiable (after 55 tests): 
expected: "--2x-8ax+15ay+24bc+cd+3cz-11dz+14abx-2acx-23ady-9axz-12bcd+9bcx-12bcy+13cdy+4dxy+11abcx+3abcy-3abcz-7abdy-10acdx+acxy+5acxz+14acyz+4adyz+13axyz+23bcdy+5bcxy+13abcdy-15abcxz-14abdxz-14bcdyz-3cdxyz-4abcdxyz"
 but got: "-1-2x-8ax+15ay+24bc+cd+3cz-11dz+14abx-2acx-23ady-9axz-12bcd+9bcx-12bcy+13cdy+4dxy+11abcx+3abcy-3abcz-7abdy-10acdx+acxy+5acxz+14acyz+4adyz+13axyz+23bcdy+5bcxy+13abcdy-15abcxz-14abdxz-14bcdyz-3cdxyz-4abcdxyz"
[("acyz",14),("bcdy",13),("ax",-8),("bc",14),("abcy",3),("bcd",-12),("ady",-12),("acxy",1),("ady",-11),("abcz",-3),("abcdxyz",-4),("acdx",-10),("axz",5),("axz",-14),("bcdyz",-14),("cdy",13),("bcxy",5),("ay",15),("dz",-11),("abcxz",-15),("acx",-2),("dxy",7),("acxz",5),("adyz",4),("bc",10),("abdxz",-14),("x",-2),("abcx",11),("cd",1),("cz",3),("abdy",-7),("abx",14),("cdxyz",-3),("bcx",9),("bcy",-12),("dxy",-3),("",-1),("axyz",13),("abcdy",13),("bcdy",10)]

- stands for zero degree monomial -1.