--- parse tree ---
[ Comment
, SoftBreak
, Equation
    False
    [ Text "a"
    , Text ","
    , Text "A"
    , Text ","
    , Code
        "typ/math/style-00.typ"
        ( line 2 , column 8 )
        (Ident (Identifier "delta"))
    , Text ","
    , Text "\1013"
    , Text ","
    , Code
        "typ/math/style-00.typ"
        ( line 2 , column 18 )
        (Ident (Identifier "diff"))
    , Text ","
    , Code
        "typ/math/style-00.typ"
        ( line 2 , column 24 )
        (Ident (Identifier "Delta"))
    , Text ","
    , Text "\1012"
    ]
, ParBreak
]
"typ/math/style-00.typ" (line 2, column 18):
Identifier "diff" not found
