<html><body><div style="color:#000; background-color:#fff; font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:13px"><div id="yui_3_16_0_1_1439990078368_32734">Hi,</div><div id="yui_3_16_0_1_1439990078368_32734" dir="ltr">Since OWL 2 is based on description Logics, let me know please more about the two notions</div><ul dir="ltr" id="yui_3_16_0_1_1439990078368_32989"><li id="yui_3_16_0_1_1439990078368_32988">Conservative extension: this concept means that we should not infere axioms that where were not entailed before an information addition? Is it true what I am saying?</li><li id="yui_3_16_0_1_1439990078368_32988">Monotonicity: additional information to an ontology should not make loose old entailments. Is it true?<br>m I saying true things? Can you correct for me the two concepts in the context of adding knowldge to an an OWL 2 DL ontology? Does this addition should respect these two principles? Are they related in a some way to ontology consistency?<br>Thks.</li></ul></div></body></html>