Divergent thinking or creative thinking whose negative injunction is not to reason solely in a single circuit or chain (particularly in a branching chain characterized by yes, no or valid, invalid eliminations). Positive injunctions in this methodology include reformulation of problems, epistemological reexamination of premises and parallel and multiple cognitive approaches to solutions, etc. Lateral thinking is said to be complementary to vertical or chain type thinking.
When NASA first started sending up astronauts, they quickly discovered that ballpoint pens would not work in 0 gravity. To combat this problem, NASA scientists spent a decade and $12 billion developing a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to over 300C. The Russians used a pencil.