Here we describe differences that users will see in the amsmath package, as the successor of amstex version 1.1. In general, commands and options that were dropped during the creation of the amsmath package are retained in the frozen version of amstex that is provided for compatibility mode use.
Not only is the unusual syntax of the primitive / fraction commands rather out of place in , but furthermore that syntax seems to be solely responsible for one of the most significant flaws in /'s mathematical typesetting capabilities: the fact that the current mathstyle at any given point in a math formula cannot be determined until the end of the formula, because of the possibility that a following generalized fraction command will change the mathstyle of the preceding material. As the side effects are a bit technical in nature, they are discussed in technote.tex rather than here.
\DeclareMathOperator{\Tr}{Tr} \DeclareMathOperator*{\xlim}{x-lim}The |*| form makes the operator name produce limit-style sub and superscripts, like max or lim. This is now the preferred method, instead of using the old command operatorname (which is, however, retained for now). The command operatornamewithlimits has been renamed operatorname*. These commands now can also be obtained through a separate package amsopn, so it's not necessary to load the entire amsmath package just to get that feature.
\sum_{\substack{first line\\second line}}This command can be used equally well in a subscript or superscript, and provides better vertical positioning (as compared to Sb, Sp) if a multiline subscript is placed on the side, as perhaps for an integral. There is also a slightly generalized alternative, an environment subarray that allows you to specify either centering or left alignment for the contents:
\sum_{\begin{subarray}{l}first line\\second line\end{subarray}}
\newcommand{\p}{$p$\nobreakdash}% for "\p-adic" \newcommand{\Ndash}{\nobreakdash--}% for "pages 1\Ndash 9"
| willproducearefoftheparentnumber`4.9', not`4.9a'.Thecountersusedbythesubequationsenvironmentare| parentequation| and| equation| andstandardusesofaddtocounter,setcounter, etc., arepossiblewiththosecounternames. Theamsmathpackage(unlikeamstex)respectsthesettingprovidedbythedocumentclassforputtingequationnumbersontherightortheleft.[Technicalnote : adocumentclassthathasleqnoasthedefaultshouldexplicitlypassthatoptiontotheamsmathpackagewithPassOptionsToPackageinorderforittobeeffective.] Thefleqnoptionforleft - alignedinsteadofcenteredequationsisnowsupported (thankstoDavidM.Jones). |
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