If entering a function over the sidebar you usually get "func{<?>}" (without whitespace). For example: abs{<?>}, sqrt{<?>}, etc. Only when entering "Factorial" over the sidebar, you get "fact {<?>}" (with whitespace). I think this should be changed in "fact{<?>}" for consistency reasons.
Confirmed the function strings are composed inconsistently into the formula editor when entering function from the "Elements" sidebar.
This issue came in with OOo and is not only from the Elements sidebar dock introduced at 4.1, but also is present in the original floating elements dialog.
Takeshi Abe committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=6984fd5a756f1e01e94da14f01df5a0e20791630 tdf#102008 Drop whitespace between "fact" and brace It will be available in 5.3.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.