x1 thinks/considers/cogitates/reasons/is pensive about/reflects upon subject/concept x2.
Also: x1 is thoughtful (one sense); x2 is mental (one sense)/intellectual (one sense) (= selpei). See also cmavo list pe'i, jijnu, menli, morji, sidbo, jinvi, se nabmi, minra, lanli, besna, saske, skami.