

define bg (*.n4, *.n6, *.n7, *.o4, *.o6, *.c5, *.c6, (*.c4,*.c7 and pyrimidine), (*.c8 and purine)) and dna 
define sm (*.o2,*.n3,*.n2,*.c2,(*.c4 and purine)) and dna
define dezox (*.C?*, *.O?*)  and dna
define ph (*.O?P, *.P) and dna
define pol (*.N??, *.O??)
define nepol (carbon or sulfur or phosphorus)
define p1 within (3.5, dezox and pol) and *:B and pol 
define p2 within (3.5, (ph and pol)) and *:B and pol
define p3 within (3.5, (bg and pol)) and *:B and pol
define p4 within (3.5, (sm and pol)) and *:B and pol
define np1 within (4.5, (dezox and nepol)) and *:B and nepol
define np2 within (4.5, (ph and nepol)) and *:B and nepol
define np3 within (4.5, (bg and nepol)) and *:B and nepol
define np4 within (4.5, (sm and nepol)) and *:B and nepol