Moebius ← +0/ׯ≤1⊕⧻⊸⊛°/×
Mertens ← |1 memo(⨬(+⊃(Mertens-1|Moebius)|1)⊸=1)
&s↯∞_10≡Mertens↘1⇡101
⊃(&p$"Crosses zero _ times"/+⌕0_1=0
| &p$"Equals zero _ times"/+
)=0≡Mertens↘1⇡1001