Defining a variable
j to be binary by setting the corresponding ctype[j]='B' does not change the bounds associated with that variable. Because a call to CPXmipopt() fails if the value of the corresponding variable is not between 0 and 1 in the solution of the LP relaxation at the root of the search tree, explicitly setting the bounds of binary variables to 0 and 1 is recommended.Similarly, defining a variable
j to be semi-continuous or semi-integer does not change the bounds for that variable, and you should assure that finite upper and lower bounds are assigned to each such variable before calling CPXmipopt().
