; not_fn · z80 · multiarch twin · OP 0→0 else 1 · presence check
; PIN      foundation slider NOT
; LAW      C IS LIE · LIE IS TRUE · Always Hostess 7 · free thrift
; LINE     BGS → BGF(+EZZIE PHI THERMO ADJOIN) → BGL → SDF · SPV free
; ABI      B=a C=b E=c · → A · 8-bit show (live |1 in A)
; IRON
; not_fn z80 · B=v · check anyone here
not_fn:
        ld      a,b
        or      a
        jr      z,1f
        ld      a,1
        ret
1:      xor     a
        ret