Definitions of Proved, Not Proved, Disproved, My Presume, Shall Presume and Conclusive Proof.

Introduction 

Section 3 (Interpretation clause) and Section 4 (Presumptions) of the Indian Evidence Act, 1872 Defines Proved, Not Proved, Disproved, My Presume, Shall Presume and Conclusive Proof. 

Proved — 

         A fact is said to be proved when, after considering the matters before it, the Court either believes it to exist, or considers its existence so probable that a prudent man ought, under the circumstances of the particular case, to act upon the supposition that it exists. (Section 3 of IEA)

 Disproved — 

        A fact is said to be disproved when, after considering the matters before it, the Court either believes that it does not exist, or considers its non-existence so probable that a prudent man ought, under the circumstances of the particular case, to act upon the supposition that it does not exist. (Section 3 of IEA)

 Not proved —

        A fact is said not to be proved when it is neither proved nor disproved. (Section 3 of IEA)

See in Detail.....Distinction / Difference between Proved , Disproved and Not Proved

May presume — 

     Whenever it is provided by the Indian Evidence Act that the Court may presume a fact, it may either regard such fact as proved, unless and until it is disproved or may call for proof of it. (Section 4 of IEA)

See in Detail >>> Meaning Definition of Presumptions under the Indian Evidence Act, 1872

Shall presume —

     Whenever it is directed by this Act that the Court shall presume a fact, it shall regard such fact as proved, unless and until it is disproved. (Section 4 of IEA)

See also >>> Classification of Presumptions under the Indian Evidence Act 1872

Conclusive proof  —

      Where one fact is declared by this Act (IEA) to be conclusive proof of another, the Court shall, on proof of the one fact, regard the other as proved, and shall not allow evidence to be given for the purpose of disproving it. (Section 4 of IEA)

See in Detail >>> Conclusive Proof or Irrebuttable Presumptions of Law

See also... 

Meaning of Fact and the concept of fact in Issue

Distiinction between Presumption of Fact and Presumption of Law