Where does simple collide?

In grammar a simple sentence is one built on a single independent clause, with one subject-predicate structure and no subordinate or coordinated clauses, as against compound, complex, and compound-complex sentences. Quirk, Greenbaum, Leech, and Svartvik's A Comprehensive Grammar of the English Language classifies sentence types on exactly this basis. The referent is a syntactic category defined by clause structure, a property of language that has nothing to do with the indivisibility of an algebraic group or the undivided blade of a leaf.[1]

Unit

A sentence consisting of exactly one independent clause

Recovery means

Not applicable

Measured by

Classified by parsing the sentence and counting its independent and subordinate clauses

In abstract algebra a simple group is a nontrivial group whose only normal subgroups are the trivial group and the whole group itself, so that it cannot be broken down by a nontrivial quotient. Dummit and Foote's Abstract Algebra develops simple groups as the indivisible building blocks into which finite groups are resolved by composition series. The referent is a structural indivisibility property of a group, a precise algebraic condition, unrelated to the clause count of a sentence or the shape of a leaf despite the shared everyday notion of being not further divisible.[2]

Unit

A group whose only normal subgroups are trivial

Recovery means

Not applicable

Measured by

Established by showing the group is nontrivial and has no normal subgroup other than the identity and itself