String concatenation is an associative, but non-commutative operation. Their multiplication is both commutative and associative. The merge function is commutative, associative, and idempotent. It is a binary form for representing simple data structures like arrays and associative arrays. Semantic priming is theorized to work because of spreading activation within associative networks. PowerShell also provides arrays and associative arrays. This technique works because addition is both associative and commutative. The Hadamard product is associative and distributive. Typically, bipolar encoding is preferred to binary encoding of the associative pairs. Hopfield networks serve as content-addressable ("associative") memory systems with binary threshold nodes. Equivariant maps for representations of an associative or Lie algebra are defined similarly. The D language also has support for associative arrays. There are two types of visual agnosia&colon; apperceptive agnosia and associative agnosia. Both associative and dissociative pathways are observed. YAML offers an "in-line" style for denoting associative arrays and lists.