If I reach a conclusion, I'm fully open to changing it, but yeu're going to have to fight for every inch of the way and prove yeurself fully. Yeu can't just go "I think yeu're wrong" and expect me to change my mind when yeu don't even know why I should. I will pull apart every piece of evidence given and make sure yeu know whot it is yeu're talking about. If yeu do, great, I'll change my mind once I know the alternative is closer to correct. I just don't change my mind on a whim is all.
Most likely, most other entp's are similar. Explore a ton of options in rapid succession, compare each, pick the one that makes the most sense at the time. Once they think they're right, yeu need to seriously know yeur stuff to change their minds.
As such, hardly "set in our way", just... don't want to change without a good reason to. If there's a good reason, then sure. Yeu just need a very good reason is all; chances are if yeu find an entp not changing, yeu're just explaining things poorly or they're finding too many gaps in yeur logic. If yeu can persevere and take on the seemingly endless stream of challenges they'll put yeur idea through, and make it to the end, then yeu can change our mind =3
If yeu give up halfway through, or hit a few loopholes or gaps in yeur argument, and can't fully fix them, then it'll be written off as just another mistake to be ignored.