# OpenType Feature File specification, section 5.f.i, example 1
# "Specifying a Chain Sub rule and marking sub-runs"
# http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html

lookup CNTXT_LIGS {
     substitute f i by f_i;
     substitute c t by c_t;
 } CNTXT_LIGS;
 
lookup CNTXT_SUB {
     substitute n by n.end;
     substitute s by s.end;
 } CNTXT_SUB;
 
feature test {
     substitute [a e i o u] f' lookup CNTXT_LIGS i' n' lookup CNTXT_SUB;
     substitute [a e i o u] c' lookup CNTXT_LIGS t' s' lookup CNTXT_SUB;
} test;