Other areas in which asymmetries are found, according to Kayne, include clitics and clitic dislocation, serial verb constructions, coordination, and forward and backward pronominalization. In arguing for a universal underlying Head-Complement order, Kayne uses the concept of a probe-goal search (based on the Minimalist program). The idea of probes and goals in syntax is that a head acts as a probe and looks for a goal, namely its complement. Kayne proposes that the direction of the probe-goal search must share the direction of language parsing and production. Parsing and production proceed in a left-to-right direction: the beginning of the sentence is heard or spoken first, and the end of the sentence is heard or spoken last. This implies (according to the theory) an ordering whereby probe comes before the goal, i.e. head precedes complement. Kayne's theory also addresses the position of the specifier of a phrase. He represents the relevant scheme as follows: S H [c...S...] The specifier, at first internal to the complement, is moved to the unoccupied position to the left of the head. In terms of merged pairs, this structure can also be represented as: This process can be mapped onto X-bar syntactic trees as shown in the adjacent diagram. Antisymmetry then leads to a universal Specifier-Head-Complement order. The varied ordering found in human languages are explained by syntactic movement away from this underlying base order. It has been pointed out, though, that in predominantly head-final languages such as Japanese and Basque, this would involve complex and massive leftward movement, which violates the ideal of grammatical simplicity. An example of the type of movement scheme that would need to be envisaged is provided by Tokizaki: [CP C [IP ... [VP V [PP P [NP N [Genitive Affix Stem]]]]]] [CP C [IP ... [VP V [PP P [NP N [Genitive Stem Affix]]]]]] [CP C [IP ... [VP V [PP P [NP [Genitive Stem Affix] N]]]]] [CP C [IP ... [VP V [PP [NP [Genitive Stem Affix] N] P]]]] [CP C [IP ... [VP [PP [NP [Genitive Stem Affix] N] P] V]]] [CP [IP ... [VP [PP [NP [Genitive Stem Affix] N] P] V]] C] Here, at each phrasal level in turn, the head of the phrase moves from left to right position relative to its complement. The eventual result reflects the ordering of complex nested phrases found in languages such as Japanese. An attempt to provide evidence for