texmath-0.12.5: test/roundtrip/cospan.native

[ EIdentifier "B"
, EUnderover
    False (ESymbol Op "\8594") (EIdentifier "f") (EGrouped [])
, EIdentifier "A"
, EUnderover
    False (ESymbol Op "\8592") (EIdentifier "f") (EGrouped [])
, EIdentifier "C"
]