LaTeX.org

Hi, where is the best reference for coding in Latex? I'm looking for something that would provide a reference for conditional statements, rules for optional arguments and other advanced topics like that. Searching the web for Advanced topics doesn't seem to go beyond creating simple macros and make ...

I've run into a weird behavior: Given the minimal example below, only the myenv correctly prints the result of \mysum. The only difference between the two environments is the order in which the variable is printed. Can anyone help me figuring how to access the variable in myenv1 in a cell other than ...