- x1=k3 is the relationship between x2=k1,
x3=k2, x3...; x1 is a property of x2.
- c1 requests/asks c2 to go back/return to x2 from x3.
- x1=g1 causes x2=xr1 to return to state x3=xr2 from state x4=xr3.
- x1 pertains to the internet/cyberspace in aspect x2.
- change version/dialect of parser