Del Grande, J. J. <br/><br/>
An introduction to the nature of proof / 
J.J. Del Grande, J.C. Egsgard, H.A. Mulligan ; [edited by] A.J. Coleman. 
 - Toronto :  Gage,  c1967. 
 - viii, 59 p. : ill. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Proof theory.<br/>Logic, Symbolic and mathematical.