Search string to filter out two values

[please55]

Hello having a bit of trouble with a search/filter.

I'm trying to filter out any books that contain the word 'vintage' or 'faber' in the publisher field.

So far I've managed -
not publisher:vintage

But the following don't seem to work -
not publisher:vintage or publisher:faber
not publisher:vintage or not publisher:faber
not publisher:vintage or faber
not publisher:vintage faber

Can I do what I want? Thanks

[Adoby]

There are two functionally identical alternatives:

not publisher:vintage and not publisher:faber

not (publisher:vintage or publisher:faber)

[please55]

Thank you. Have to admit I don't get the logical process that:
not publisher:vintage or not publisher:faber
isn't actually what I'm trying to specify.

[theducks]

Open the Tag browser: Publisher

click Publisher #1 twice (red minus will show)
Hold down the control key
repeat for each additional Publisher

BTW at the bottom of the tag browser there is a crossed tools Icon: choose Match all

[itimpi]

Originally Posted by please55

Thank you. Have to admit I don't get the logical process that:
not publisher:vintage or not publisher:faber
isn't actually what I'm trying to specify.

This will always equate to true as with the ‘or’ used in this way it could only return false was if the publisher was simultaneously ‘vintage’ AND ‘Fabre’. Under any other condition at least one side of the ‘or’ would be true so the expressions as a whole would equate to true.

[chaley]

Originally Posted by please55

Thank you. Have to admit I don't get the logical process that:
not publisher:vintage or not publisher:faber
isn't actually what I'm trying to specify.

Entering Boolean Algebra zone ...

It doesn't work because the expression you wrote will match any publisher that isn't both vintage and faber, which clearly can never happen. Why does it match?

The OR operator returns TRUE if either the left or the right expression returns TRUE. The only way OR can return FALSE is if both the left and right return FALSE. Consider a book with publisher "vintage". The first expression (not publisher:vintage) returns FALSE, but the second expression (not publisher:faber) returns TRUE. FALSE or TRUE equals TRUE. The same is true for a book with publisher "faber". The first expression returns TRUE because faber is not vintage. The second expression returns FALSE because faber is faber. TRUE or FALSE returns TRUE.

You are looking for books that are neither vintage nor faber. In other words you are looking for books where either (not both) the left or the right expression returns FALSE. This requires the AND operator, which returns TRUE if both the left and right expressions return TRUE, otherwise it returns FALSE.

FWIW 1: this site shows the "truth tables" for boolean operators such as AND and OR. A "truth table" provides the result for all possible inputs.

FWIW 2: Adoby's response makes use of something called De Morgan's laws. These "laws" provide conversions between AND and OR expressions so that the expressions provide the same answer.

[please55]

Originally Posted by chaley

Entering Boolean Algebra zone ...

It doesn't work because the expression you wrote will match any publisher that isn't both vintage and faber, which clearly can never happen. Why does it match?

The OR operator returns TRUE if either the left or the right expression returns TRUE. The only way OR can return FALSE is if both the left and right return FALSE. Consider a book with publisher "vintage". The first expression (not publisher:vintage) returns FALSE, but the second expression (not publisher:faber) returns TRUE. FALSE or TRUE equals TRUE. The same is true for a book with publisher "faber". The first expression returns TRUE because faber is not vintage. The second expression returns FALSE because faber is faber. TRUE or FALSE returns TRUE.

You are looking for books that are neither vintage nor faber. In other words you are looking for books where either (not both) the left or the right expression returns FALSE. This requires the AND operator, which returns TRUE if both the left and right expressions return TRUE, otherwise it returns FALSE.

FWIW 1: this site shows the "truth tables" for boolean operators such as AND and OR. A "truth table" provides the result for all possible inputs.

FWIW 2: Adoby's response makes use of something called De Morgan's laws. These "laws" provide conversions between AND and OR expressions so that the expressions provide the same answer.

Thank you everyone. This always tricked me up when I did intro CS courses.

@ducks picked up this method after rereading manual shortly before coming back here. Somehow escaped my mind to use windows ctrl function for multiple selection.