Lack of formal syntax undermines Ada

Ada does not have a formal syntax. The LRM provides "syntax rules"
section by section, then collectively in Annex P. The resulting
woolly grammar is well-known to be ambiguous (e.g. is X:=Y(Z) an
assignment from a function call, array indexing or something
else?). It mixes lexical and syntactical information. It cannot
be used as the input to a parser generator. The interpretation
necessary via other sections of the LRM risks making the language
as a whole indefinite.

Ada is designed for the construction of high-integrity software
by validated compilers. Would it not be better to have formal
Ada lexical and syntactic rules, expressed in regular expression
and BNF format respectively, even if such rules turn out to be
not particularly readable?

As an example, my parser is having trouble with the fragment:
task type TT is
   pragma priority(12);
end TT;
Is this legal Ada95 syntax or not?

Regards,
Chris Noonan