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Maxterm with example

Short answer

A maxterm is an OR term that includes every variable exactly once, in true or complemented form, and is 0 for exactly one input combination. For example, for variables A,B,C, maxterm M2 = A+B'+C is 0 only when A=0,B=1,C=0.

What do you mean by Max term? Explain with example.

A maxterm is a sum (OR) term that contains all the variables of the function exactly once, each either in true or complemented form. A maxterm is 0 for exactly one input combination and 1 for all others.

How to write a maxterm: for the input combination that should give 0, write a variable as it is if its value is 0, and complemented if its value is 1. Maxterm MiM_i is the one that is 0 at decimal input ii.

For three variables A, B, C:

A B CMaxtermSymbol
0 0 0A+B+CA+B+CM0M_0
0 0 1A+B+C‾A+B+\overline{C}M1M_1
0 1 0A+B‾+CA+\overline{B}+CM2M_2
0 1 1A+B‾+C‾A+\overline{B}+\overline{C}M3M_3
1 0 0A‾+B+C\overline{A}+B+CM4M_4
1 0 1A‾+B+C‾\overline{A}+B+\overline{C}M5M_5
1 1 0A‾+B‾+C\overline{A}+\overline{B}+CM6M_6
1 1 1A‾+B‾+C‾\overline{A}+\overline{B}+\overline{C}M7M_7

Each maxterm is the complement of the minterm with the same number: Mi=mi‾M_i = \overline{m_i}.

Example: let F be 0 only for inputs 000, 010 and 101. The function is the AND (product) of the maxterms for these rows (the canonical POS form):

F=M0⋅M2⋅M5=ΠM(0,2,5)=(A+B+C)(A+B‾+C)(A‾+B+C‾)\begin{aligned} F &= M_0 \cdot M_2 \cdot M_5 = \Pi M(0,2,5) \\ &= (A+B+C)(A+\overline{B}+C)(\overline{A}+B+\overline{C}) \end{aligned}

Check: for input 010, the second factor A+B‾+C=0+0+0=0A+\overline{B}+C = 0+0+0 = 0, so F = 0. For any other input not in the list, all three factors are 1, so F = 1.

✓ Answer checked by Claude Opus 5.5 (high effort)

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