[NTG-context] Another TikZ problem with "!"

Hi! Color is not the only place where TikZ treats "!" in a special way. For example, in TikZ/LaTeX you can say: \coordinate (A) at (0, 0); \coordinate (B) at (1, 0); \coordinate (C) at ($ (A)!.3!(B) $); % z.C = .3[z.A, z.B] in MetaPost \coordinate (D) at (2, 1); \coordinate (E) at ($ (A)!(B)!(D) $); % projection of (B) to (A)--(D). This code fails in ConTeXt because "!" is made a "normal" character.