Added pre-test to avoid loosing the process when loading library(pce).
Added pre-test to avoid loosing the process when loading library(pce).

koryonik/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel