t / t4034 / matlab / preon commit test-lib: turn off "-x" tracing during chain-lint check (2a01ef8)
   1(1) (-1e10) 'b';
   2[a] {a} a.b;
   3~a;
   4a*b a.*b a/b a./b a^b a.^b a.\b a.';
   5a+b a-b;
   6a&b a&&b a|b a||b;
   7a<b a<=b a>b a>=b;
   8a==b a~=b;
   9a,b;