> why stop there? The example that comes to mind is "Courier 12pt is the only font ever for screenplays". It's required to convey a screenplay, to my mind, like using Fraktur is required in the math space.
The screenplay is still being written in letters. Mathematical ℝ is more accurately thought of as an ideogram than a letter. If you were to write "let r be a member of ℝ", the "ℝ" would be structurally parallel to the full word "member", not to the "r" within it.
Courier for screenplays is a choice you make at the document level; blackboard bold for mathematical entities is not. ℝ is always ℝ no matter what styles apply to your document.
The screenplay is still being written in letters. Mathematical ℝ is more accurately thought of as an ideogram than a letter. If you were to write "let r be a member of ℝ", the "ℝ" would be structurally parallel to the full word "member", not to the "r" within it.
Courier for screenplays is a choice you make at the document level; blackboard bold for mathematical entities is not. ℝ is always ℝ no matter what styles apply to your document.