Show a few TeX math commands with the corresponding Unicode symbol in Emacs

latex-font-lock-keywords.el

;; Fancy stuff
(setq cefstat/fancy-TeX-pairs
      '(("le" . ?≤)
	("ge" . ?≥)
	("infty" . ?∞)
	("times" . ?⨯)
	("in" . ?∈)
	("ni" . ?∋)
	("wedge" . ?∧)
	("partial" . ?∂)
	("int" . ?∫)
	("oint" . ?∮)
	("nabla" . ?∇)
	("to" . ?→)
	("rightarrow" . ?→)
	("mapsto" . ?↦)
	("cup" . ?∪)
	("cap" . ?∩)
	("subset" . ?⊂)
	("subseteq" . ?⊆)
	("supset" . ?⊃)
	("supseteq" . ?⊇)
	("pm" . ?±)
	("mp" . ?∓)
	("setminus" . ?∖)
	("gg" . ?≫)
	("ll" . ?≪)
	("approx" . ?≈)
	("hbar" . ?ℏ)
	("ell" . ?ℓ)
	;; greek
	("alpha" . ?α)
	("beta" . ?β)
	("Beta" . ?Β)
	("gamma" . ?γ)
	("Gamma" . ?Γ)
	("delta" . ?δ)
	("Delta" . ?Δ)
	("epsilon" . ?ϵ)
	("varepsilon" . ?ε)
	("zeta" . ?ζ)
	("eta" . ?η)
	("theta" . ?θ)
	("Theta" . ?Θ)
	("vartheta" . ?ϑ)
	("iota" . ?ι)
	("kappa" . ?κ)
	("lambda" . ?λ)
	("Lambda" . ?Λ)
	("mu" . ?μ)
	("nu" . ?ν)
	("xi" . ?ξ)
	("Xi" . ?Ξ)
	("omicron" . ?ο)
	("pi" . ?π)
	("Pi" . ?Π)
	("varpi" . ?ϖ)
	("rho" . ?ρ)
	("sigma" . ?σ)
	("Sigma" . ?Σ)
	("varsigma" . ?ς)
	("tau" . ?τ)
	("upsilon" . ?υ)
	("phi" . ?φ)
	("Phi" . ?Φ)
	("varphi" . ?ϕ)
	("chi" . ?χ)
	("psi" . ?ψ)
	("Psi" . ?Ψ)
	("omega" . ?ω)
	("Omega" . ?Ω)
	))

(setq cefstat/fancy-TeX-pairs-bold
      '(("R" . ?R)
	("Z" . ?Z)
	("Q" . ?Q)
	("S" . ?S)
	("T" . ?T)
	("N" . ?T)
	("setR" . ?R)
	("setZ" . ?Z)
	("setQ" . ?Q)
	("setS" . ?S)
	("setT" . ?T)
	("setN" . ?T)
	("dd" . ?d)
	("ii" . ?i)
	))

(defun cefstat/fancy-TeX ()
  (progn
    (dolist (p cefstat/fancy-TeX-pairs)
      (font-lock-add-keywords
       nil `((,(concat "\\(\\\\" (car p) "\\)[^a-zA-Z]")
	      (1 (progn (compose-region (match-beginning 1) (match-end 1) ,(cdr p))
			nil))))))
    (dolist (p cefstat/fancy-TeX-pairs-bold)
      (font-lock-add-keywords
       nil `((,(concat "\\(\\\\" (car p) "\\)[^a-zA-Z]")
	      (1 (progn (compose-region (match-beginning 1) (match-end 1) ,(cdr p))
			nil))
	      (1 'font-latex-bold-face t)))))))


(add-hook 'LaTeX-mode-hook 'cefstat/fancy-TeX)