Salvete, afaics, the following three mathml snippets encode exactly the same thing: ---[1]------------ <mrow> <mi>a</mi> <mo>::</mo> <mi>b</mi> </mrow> ---[2]------------ <mrow> <mi>a</mi> <mo>::</mo> <mi>b</mi> </mrow> ---[3]------------ <mrow> <mi>a</mi><mo>::</mo><mi>b</mi> </mrow> However, I only get the expected output from the third version. Any workaround or bugfix? Regards, Christopher