Ep types would be the "introverted" extratim of Socionics, and this is described from the very begining.

In Socionics E technically equals Extrotim not Extrovert because these are not identical in socionics.

Quote Originally Posted by Dual nature of man
Jung's terms "extroverted" - "introverted", we have replaced the now-popular extrovert - introvert, but believe that the more appropriate term would be extrotim - introtim made by analogy with {krechmerovskimi schizotim terms - cyclotron}(would like a good translation of this part), because after the work of Eysenck, according to tests which extended the trend of every social person, call an extrovert, and each closed - introvert, these terms are ambiguous.


The analogy for E/I in socionics is
object/field from physics and introverted and extroverted are only correlated manifestations of behavior.

Typing I have for Handi is IEE