In the sentence:
Merging two forces that pull in opposing directions requires some creativity.
Going through lists of words here and there, I didn't find anything that would fit in this context. My first thought was that the meaning of pull here was closed to "stay" ("stay" in opposing directions). But there's no such meaning of it.
To pull means the first definition of your second link.
move someone/something towards you
For example, let's say there are anti-Trump Republicans and pro-Trump Republicans. They oppose each other because they have different views on his candidacy.
They are trying to pull (attract) each other toward them in opposing directions. However, merging (combining) those two forces (groups / parties) will require some creativity (good ideas, new slogans, etc).
The above is just an example to show how the verb to pull can work and in the above context, to pull could mean to attract a person or people which is listed in your first link. To pull could have various meanings, but it depends on what "forces" are in your context and all the meanings are derived from "to move someone/something towards you".
To pull doesn't mean to stay.
I think you are familiar with tug of war. Look at No. 2 definition:
a contest in which two teams pull against each other at opposite ends of a rope with the object of pulling the middle of the rope over a mark on the ground
You will understand what the verb means more easily if you see the picture above.
X pull[s] Y means that:
It's possible to pull things to move them around, and it's also possible to specify or imply a location for pull if you say "X pulls from Y", or omit specifying anything if the "thing" being pulled is abstract or unknown.
Merging two forces that pull [from Y] in opposing directions
We are talking about forces themselves, and not caring exactly what they are trying to "force", so the "from Y" is omitted.
FWIW sounds like a game programming math book talking about vectors - if you have 2 forces acting on an object, how do you determine the single combined force to apply movement to the object for the next display frame or game tick?
In addition to Rathony's examples, there is also the verb to pull apart. Thesaurus.com offers the following synonyms for pull apart:
admonish, berate, castigate, chastise, chide, denounce, discipline, rebuff, rebuke, reprimand, reproach, scold, abuse, animadvert, asperse, attack, backbite, blame, cavil, contemn, denigrate, deprecate, disapprove, disparage, impugn, incriminate, judge, knock, lecture, ostracize, remonstrate, reprehend, reprove, upbraid, carp at, cut up, exprobate, find fault with, get after, look askance, pick apart, read out, take to task, tear apart, and tell off.
Dictionary.com includes the following definition as well:
- to draw or tug at with force.
