What is the difference between Inclusive and Exclusive OR?

16
votes

I have been studying some Business Process Execution Language (BPEL) and the associated modelling system (BPMN) where the designer needs to learn about inclusive and exclusive gateways for process flow. Thanks very much for any help and a general explanation of the terms would be enough assuming the same rules apply.

This is some technical text I am trying to understand in response to Mark- For simple links that join two activities, the status defaults to true so the target activity always gets executed. However, if a transition condition is applied to the link, such as a test of the value contained in a process variable, the status may be set to 'false', blocking the execution of any target activities. If a target has multiple links then the decision to execute or block is based on the OR of the individual link status values. Only one link status need be true for the target to execute; hence transition conditions can be used to map the Inclusive OR gateway of BPMN

8
xmlbpelbpmn
This isn't programming, this is "English". While I understand that it occurs in a programming context, it's really an English language question, not a programming question. – S.Lott
I understand but please see my comment to Mark extracted from the text I am reading. Its very technical English. – fwc
Please put your "comment to Mark" in the question so that the question is complete and readable and understandable by everyone. – S.Lott

8 Answers

43
votes
  • Inclusive or: A or B or both.
  • Exclusive or: Either A or B but not both.

15
votes
A B OR XOR  
1 0  1  1  
1 1  1  0  
0 1  1  1  
0 0  0  0
9
votes

Considering the value for the statement "A OR B":

Inclusive OR allows both possibilities as well as either of them. So, if either A or B is True, or if both are True, then the statement value is True.

Whereas Exclusive OR only allows one possibility. So if either A or B is true, then and only then is the value True. If both A and B are True, even then the statement's value will be False.

Example for Exclusive OR: At a restaurant, you are offered a coupon which entitles you to eat either a Sandwich OR a Burger. This is an exclusive OR statement in English language. You can choose either one of them, but not both.

7
votes

The difference is what happens with both components are true. With inclusive or, the result is also true. With exclusive or, the result is false.

Exclusive or is kinda like Highlander: There can be only one. :-)

4
votes

INCLUSIVE 'OR' : Logic OR means its output is 'ON' if any of the input is 'ON'. It includes 'both' inputs are 'ON' (At least one input is 'ON').

EXCLUSIVE 'OR' : It is same as Inclusive OR, with the (only) EXCEPTION is while 'both' inputs are 'ON' then the output goes OFF, (NOT ON as in the Inclusive OR) and hence the name EXCLUSIVE 'OR'.

3
votes

as a result table:

inclusive or:

A B Result
0 0 0
1 0 1
0 1 1
1 1 1

exclusive or:

A B Result
0 0 0
1 0 1
0 1 1
1 1 0

so, aus you can see, an exclusive or give false if both are true, cause its exclusive means A or B but not both

0
votes

well on a totally different note - and getting back to everyday English conversation the inclusive/exclusive thing can be made clearer:

Do you want tea or coffee? (meaning, fancy something to drink?) = inclusive or Do you want tea or coffee? (meaning you have to choose between the two) = exclusive

0
votes

In inclusive OR, the condition is atleast one of the two must be true. Whereas, in exclusive OR, BOTH cannot be true,atleast one must be true.