It is true that the algebra filter supports a strict subset of the expressions supported by the TeX filter. However the syntax of the algebra filter is not a subset of the syntax of the TeX filter. For example, the algebra syntax for @@int(x^2 dx,0,1)@@ is @@@int(x^2 dx,0,1)@@@ as opposed to http://moodle.org/mod/forum/discuss.php?d=5402 for some examples.
\int_0^1 x^2 dx in the TeX filter. See the following discussion: