Ambient Isotopy

A continuous one-parameter family of homeomorphisms H_t: M → M, t ∈ [0,1], of an ambient space M with H_0 = id_M such that H_1 carries one embedding or submanifold A ⊂ M to another embedding or submanifold B ⊂ M. Two embeddings are ambiently isotopic if they are related by such a family.