Is the expression (a=b) = k UB?

Question

Is (a = b ) = k undefined behavior if a,b and k are of int type and properly initialised?

thanks

Answer 1

Looks UB to me. a is getting modified more than once b/w two sequence points.

The result of (a=b) is an lvalue¹ which is a reference to a

_{1 The result of the assignment operation is the value stored in the left operand after the assignment has taken place; the result is an lvalue ($5.17/1).}