//(p+3)/2 + gcd(p-1,3) algebras
<a,b,c|ca-bab,cb,pa,pb-baa,pc,class=4>
<a,b,c|ca-bab,cb,pa-babb,pb-baa,pc,class=4>
<a,b,c|ca-bab,cb,pa-wbabb,pb-baa,pc,class=4>(p=1 mod 3)
<a,b,c|ca-bab,cb,pa-w^2babb,pb-baa,pc,class=4>(p=1 mod 3)
<a,b,c|ca-bab,cb,pa-xbabb,pb-baa,pc-babb,class=4>(all x, x~-x)
