A {r,u,v,y}
B {r,v,w,x}
C {r,u,w,z}
t and s are on the outsides.
find (A intersect B) intersect Cc
(A union B union C)c
B {r,v,w,x}
C {r,u,w,z}
t and s are on the outsides.
find (A intersect B) intersect Cc
(A union B union C)c