Production Model with Disjuncts

[krzysztofpostek]

• [x] title: "Production Model with Disjuncts" = > Production Model with Disjunctions
• [ ] we need to write something like "the starting production model is..." in the beginning before the first code snippet
• [ ] pls add a word of comment that the latest code snippet is equivalent to the penultimate one except for the way the disjuctions are defined
• [ ] in general a narrative is missing a bit in this example