#MST(G): Minimal spanning tree
MST:=proc(G) local n,E,DT,SP,E1,cha,rec,i1:

n:=G[1]:
E:=G[2]:
DT:=G[3]:
SP:={}:
E1:=E minus SP:


while nops(SP)<n-1 do
cha:=E1[1]:
rec:=DT[cha]:

for i1 from 2 to nops(E1) do
 if DT[E1[i1]]<rec then
  cha:=E1[i1]:
  rec:=DT[E1[i1]]:
fi:
od:
if member(cha[2],CC([n,SP],cha[1])) then
 next:
else
SP:=SP union {cha}:
E1:=E1 minus {cha}:
fi:
od:

[n,SP]:
end: