What does the sign that looks like $\geq$ except with the bottom line being sloped mean?

Question

I'm referring to this symbol: $\geqslant$.

No symbol list I've come across mentions it. I saw it in the book Pattern Recognition and Machine Learning by Christopher M. Bishop.

Answer 1

An example of the symbol's context can be found on p19 of Bishop - Pattern Recognition and Machine Learning:

$\qquad\begin{align*} p(x) &\geqslant 0 \\ \int p(x)\,\mathrm{d}x &= 1 \end{align*}$

The symbols $\geq$, $\geqslant$ and >=, all mean the same thing: Greater than or equal to.

The same applies to its converse: $\leq$, $\leqslant$ and <=, all mean: Less than or equal to.

Context for the latter symbol:

$\qquad\displaystyle f\left(\sum_{i=1}^M \lambda_i x_i\right) \leqslant \sum_{i=1}^M \lambda_i f(x_i)$

The differences can be attributed to the character set available, and/or the particular font that is used. In this particular book, the author specifies, on page viii, than they have used $\LaTeX$.