Is this pseudo code or some programming language

Question

I'm reading about graph traversal in this PDF and see some unfamiliar symbols. Is this code sample just pseudocode or is it some language I haven't seen before? If pseudocode, does it have some formal schema that will let me look up the unfamiliar symbols?

Bitmap sample here:

Answer 1

It is a formal mathematical style of pseudocode sometimes referred to as pidgin code. Very few real languages use symbols like that, but there are some, such as APL.

There is no "glossary of symbols" per se, because every author uses his or her own flavor, but they tend to follow commonly-understood math notation.

This particular piece of code on BFS is very widely quoted. Wikipedia's BFS article has an "ASCII" translation of it.