Exemple de calcul
W=(137-19)-(28-142)-(-19+137)+(28-42)
=137-19-28+142+19-137+28-42
= 118-28+142+19-137+28-42
=90+142+19-137+28-42
=232+19-137+28-1)42
=251-137+28-42
=114+28-42
=142-42
=100
X=-(-73+29-12-36)-(121-56)+(-89-138)+111
=-89
Y=(112,5-23,5)-(-11,5-24,5)+(112,5+11,5)
=249
Z=-(138,5-94)+(-1+26,5)+212-14+18
=197
