 If we replace the phrase "isomorphic to a subgroup of a quotient of" with "isomorphic to a subgroup of" in the definition of "SQ-universal", we obtain the stronger concept of S-universal (respectively S-universal for/in formula_9).The Higman Embedding Theorem can be used to prove that there is a finitely presented group that contains a copy of every finitely presented group.If formula_36 is the class of all finitely presented groups with soluble word problem, then it is known that there is no uniform algorithm to solve the word problem for groups in formula_36.