a   b   i x          y          sa  sb  si sx         sy         snonesuch
pan pan 1 0.34679014 0.72680286 pan pan 1  0.34679014 0.72680286 (absent)
eks pan 2 0.75867996 0.52215111 eks pan 2  0.75867996 0.52215111 (absent)
wye wye 3 0.20460331 0.33831853 wye wye 3  0.20460331 0.33831853 (absent)
eks wye 4 0.38139939 0.13418874 eks wye 4  0.38139939 0.13418874 (absent)
