Having been recently caught by the mathematical fever, I'm amazed the quantity of strange symbols that appear. For example, what means the symbol that ressembles a cross with the vertical segment skewed, the symbol that appears in this explanation of Gauss lemma?http://mathworld.wolfram.com/GausssLemma.html

Having been recently caught by the mathematical fever, I'm amazed the quantity of strange symbols that appear. For example, what means the symbol that ressembles a cross with the vertical segment skewed, the symbol that appears in this explanation of Gauss lemma?http://mathworld.wolfram.com/GausssLemma.html

I'm not sure if it's possible to make that symbol here, so let me use @ in it's place for this post. p @ m means p does not divide evenly into m (p/m is not an integer) and is read "p does not divide m". For example 5 @ 12 and 4 @ 7.

The vertical line without the cross means is the negation, and means"divides evenly" (http://mathworld.wolfram.com/Divides.html). For example 5|10 and 4|20.

Its fairly standard to put a "slash" (a skewed crossing line) through a symbol to mean "not".