Alpatva (sparseness) arises from sparse svara usage; it is twofold (samnyāsa-based and antaramārga-based)
Body (pseudocode)
FUNCTION compute_alpatva(svara_sequence):
IF svaras_used_sparsely(svara_sequence):
alpatva = TRUE
type IN {samnyasa_gata, antaramarga}
RETURN {alpatva: TRUE, type: type}
RETURN {alpatva: FALSE}