The Conditions Logic in the Internal Workflow is controlled through the Custom Conditions Logic toggle button. If the toggle button is not enabled then the default logic prevails.
By default, when the toggle button is not enabled, the Conditions logic uses AND operator between all the conditions laid out.
When the user enables the toggle button, they can customize the conditions logic using the desired operators. In the following image, OR operators are used instead of the default AND operators.
Only AND/OR operators are allowed in the Custom Conditions Logic. Any other word, operator or sign gives error.
The case of text (small, All etc.) for the operator does not count. You can even mix the case.
Conditions will be evaluated from Left to right. 1 OR 2 AND 3 will be read as (1 or 2) AND 3. The order of evaluation precedence can be altered using brackets.
Like the Trigger node, conditions on any node further down, work the same way along with their Custom Conditions Logic toggle button.