How do I ensure the user inputs a minimum x value that's actually smaller than the maximum x value?

I am trying to get the user's minimum and maximum x values for the quadratic equation, but I don't know how to code to make sure that the minimum value doesn't equal or exceed the maximum value. Please help.

% Plotting a User-Entered Quadratic Function %

user_input = input(['Enter a, b, and c values for the quadratic equation',...
    '\nax^2 + bx + c = 0. Input all three values in this form [a b c].',...
    '\nInput values (including brackets): ']);


user_input1 = input(['Enter the minimum and maximum values of x in',...
    '\nthe form [a b]: ']);

Answer 1

[David Fletcher]

isError = 1;

while isError
    user_input1 = input(['Enter the minimum and maximum values of x in',...
        '\nthe form [a b]: ']);
    isError = ~(user_input1(1)<user_input1(2));
end

[Alexis Williams]

Thank you! This helped a lot.