I just wrote this version and it solved it successfully: A chemist must transport three substances from his home laboratory to his office. The three substances

I just wrote this version and it solved it successfully: A chemist must transport three substances from his home laboratory to his office. The three substances react with one another in dangerous ways, but only when they are unsupervised by the chemist. The substances are labelled with code names, namely Wotan, Gitan and Catan. They can only be safely transported in a special containment vessel, and this vessel can only transport one substance at a time. The unsupervised dangerous reactions are as follows: if Wotan is left with Gitan, they explode. If Gitan is left with Catan, they cause a nuclear reaction. Wotan and Catan, however, can be safely left alone together. How can the chemist transport all three substances to his office safely?