Similar considerations are raised by the appellants' further submission that the Commission is not in the present case entitled to report a finding in relation to them that corrupt conduct may have occurred, may be occurring or may be about to occur. They concede that such a finding may be reported where a matter has been referred to the Commission by Parliament. One of the functions of the Commission under s. 13(2)(a)(i) in that event is to determine "whether any corrupt conduct may have occurred, may be occurring or may be about to occur". That is not expressed to be a function of the Commission where a matter is not referred to it by Parliament, its relevant duty (under s. 3(2) a function includes a duty) then being merely to investigate any circumstances implying, or any allegations, that corrupt conduct may have occurred, may be occurring or may be about to occur and to investigate any conduct which, in its opinion, is or was connected with or conducive to corrupt conduct. Again the appellants are able to rely upon the maxim expressum facit cessare tacitum, having regard to the express provision made by s. 13(2)(a) where a matter is referred to the Commission by Parliament. That suggests that, had the legislature intended the Commission otherwise to have the function of making findings of corrupt conduct, it would have made specific provision for it to do so. Not only does the presence of s. 13(2)(a) suggest that, but so also does s. 74(5), where specific power is expressly given to the Commission to make a finding of a particular kind. Moreover, the power given to the Commission in the case of a reference by Parliament to determine whether corrupt conduct may have occurred, may be occurring or may be about to occur, is a power to make a finding of a tentative kind only which, together with the limited nature of the findings which may be expressed pursuant to s. 74(5), indicates that the Commission was intended to have only a restricted capacity to make findings, its principal roles being to investigate, educate and advise and to enlist and foster public support against corrupt conduct.