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4.2.2 Construct Boolean expressions using the operators in 4.2.1


(No teaching notes for this one.

JSR Notes:

See the actual syllabus for the symbols chart. ***And note that the correct xor symbol is with a + in a circle, not an x, as is shown several times in the textbook..

The only thing needed here is a clarification of what is being asked.  And yes, it is as straight-forward as it seems.  You just need to know the symbols and what they stand for; be able to go back and forth between symbols and words, and words and symbols.  Do note particularly that the textbook is wrong with its depiction of the xor: it’s a + sign inside a circle, not an x inside a circle; so it’s the way it appears in the syllabus.

So you might get a question like one of the following:

“Construct the Boolean expression for A xor C and (not B and C.)”
Answer:

sdsdf

or “Write out the Boolean expression represented by the following:.”

sadsdf

Answer:
not B or A and not (B xor (C and D))

It can get tricky knowing where to put the parenthesis, but they should always be placed anyway, to indicate precedence – so when in doubt, add parentheses where they make sense.

Precedence:
The only precedence you need to know is that parenthesis always take precedence, and and takes precedence over or. Other than that, just take them in order from left to right.