In the user's guide for the amsmath
package (Version 2.1) on page 3, the descriptions for the options leqno
and fleqn
are as follows:
leqno
: Place equation numbers on the left.
fleqn
: Position equations at a fixed indent from the left margin rather than centered in the text column.
However, the meaning of the abbreviations "leqno" and "fleqn" are not immediately clear from these descriptions. In a response on this link, the following meanings were suggested:
leqno
: left equation numbers
fleqn
: flush left equations
According to Merriam-Webster Dictionary's entry for "no," which states that it is derived from the Latin word "numero" (ablative of "numerus"), it can be understood as meaning "number."
Therefore, it can be inferred that leqno
stands for "left equation no". However, it is unclear what the "n" in fleqn
stands for if it is interpreted as "flush left equations."
I was not able to find a definitive explanation for the abbreviations leqno
and fleqn
and their corresponding words through a search engine. It seems that the suggested meanings are based on reasonable deductions/guesses.
PS: English is not my native language, so please forgive any typos or inaccuracies in my expression. If there is any unclear part of my question, please let me know, and I will be happy to rephrase it until we can communicate effectively. Similarly, I am willing to do what I can to help in the process of finding an answer.
fleqn
does stand forflush left equations
i.e. "flush left equations". In English, the letters for an abbreviation do not need to immediately follow each other so I think this is the same too.eqn
is typically used as the abbreviation forequation
in my previous experience but I do not know the internals ofamsmath
so cannot be authoritiveamsmath
can give an authoritative explanation. Personally, I even feel that this question has already been resolved.fleqn
exists also in the kernel andamsmath
just redefines it, so the question is probably unrelated toamsmath
.\fleqn
does not mean "flush to the left margin", at least inamsmath
. The "fixed indent" is meaningful, and it has the width\mathindent
(default 30pt).