x1=tcit1=s3 is a modal (BAI, «fi'o broda», PU, etc.) of/based on/derived from x2=tcit3=tcin1 (e.g. «bai», «se cabna» ({se} used for tense)) for sumti x3=tcit2=s1 of selbri x4=s2.
x1=p1=b2 uses language / language feature / complete language / language dialect or variation / dictionary / semantics / other language standard or specification or open source fork x2=p2=b1 with scope / for text / purpose / to express / communicate x3=p3=b3; x1 is using / declaring language / language extension x2.