bn.fit objects, and dump
  bn and bn.fit objects into files for other programs to read.# Old (non-XML) Bayesian Interchange format.
read.bif(file, debug = FALSE)
write.bif(file, fitted)# Microsoft Interchange format.
read.dsc(file, debug = FALSE)
write.dsc(file, fitted)
# HUGIN flat network format.
read.net(file, debug = FALSE)
write.net(file, fitted)
# Graphviz DOT format.
write.dot(file, graph)
bn.fit.bn or bn.fit.TRUE a lot of debugging output is
    printed; otherwise the function is completely silent.read.bif, read.dsc and read.net return an object of class
  bn.fit. write.bif, write.dsc, write.net and write.dot
  return NULL invisibly.