::vowel:: = aäeioöuü
::consonant:: = b|c|ch|ck|d|dt|f|g|h|j|k|l|m|n|p|pf|r|s|sch|t|tsch|tz|tzsch|v|w|z

% Final schwa
e -> ə / _ #

% Open syllable lengthening
i -> ie / _ #|(::consonant::)[::vowel::]
e -> ee / _ #|(::consonant::)[::vowel::]
ü -> üh / _ #|(::consonant::)[::vowel::]
ö -> öo / _ #|(::consonant::)[::vowel::]
u -> uh / _ #|(::consonant::)[::vowel::]
o -> oo / _ #|(::consonant::)[::vowel::]
a -> aa / _ #|(::consonant::)[::vowel::]