In math mode, does the space character between tokens have a meaning?

[ParaN3xus]

This is related to the symbol’s math class. You can try and observe it’s behavior with code below.

Code and preview

#let classes = ("normal", "punctuation", "opening", "closing", "fence", "large", "relation", "unary", "binary", "vary")

#table(
  columns: 2,
  align: center + horizon,
  "class", "behavior",
  ..classes
    .map(c => {
      let symbol = math.class(c, "test")
      (
        c,
        $
          "with space:" &a symbol b \
          "without space:" &a#symbol;b
        $,
      )
    })
    .flatten()
)

The math class of "GF" is normal so spaces around it counts.