13. A computer implemented method comprising: receiving by a search engine, operating on a computing device, from a content searching or consuming application, a search expression having a first and a second proximally associated atomic sub-expression, the search engine and the content searching or consuming application being operated on one or more different or same computing devices; receiving content nominally associated with the search expression, or access information of the content, by the search engine; generating, by the search engine, one or more scores for one or more structures of the content indicative of relative relevance of the content or one or more portions of the content to the search expression, wherein the generating of a score for a structure is based at least in part on a distance function and a scoring function, wherein the structure have sub-structures structurally describing at least a portion of the content, and having content nodes and/or text strings, wherein the sub-structures are hierarchically organized with the one or more portions of the content in a sub-structure at a level respectively assigned one or more positions according to a geometry established for that level, wherein the distance function measures distances between sub-structures within the structure, and the scoring function is positionally sensitive, yielding different scores for different occurrence positions of either or both of the proximally associated first and second atomic sub-expressions in the sub-structures; and conditionally providing or not providing the content or one or more portions of the content, or access information of the content or one or more portions of the content, to the content searching or consuming application, by the search engine, based at least in part on the generated one or more scores; wherein the generating of a score for a structure further includes at each level, linearly iterating over one or more portions of the content at the level to capture potential of a portion to influence other portions of the level, and influence received by a portion from the other portions of the level.
13. A computer implemented method comprising: receiving by a search engine, operating on a computing device, from a content searching or consuming application, a search expression having a first and a second proximally associated atomic sub-expression, the search engine and the content searching or consuming application being operated on one or more different or same computing devices; receiving content nominally associated with the search expression, or access information of the content, by the search engine; generating, by the search engine, one or more scores for one or more structures of the content indicative of relative relevance of the content or one or more portions of the content to the search expression, wherein the generating of a score for a structure is based at least in part on a distance function and a scoring function, wherein the structure have sub-structures structurally describing at least a portion of the content, and having content nodes and/or text strings, wherein the sub-structures are hierarchically organized with the one or more portions of the content in a sub-structure at a level respectively assigned one or more positions according to a geometry established for that level, wherein the distance function measures distances between sub-structures within the structure, and the scoring function is positionally sensitive, yielding different scores for different occurrence positions of either or both of the proximally associated first and second atomic sub-expressions in the sub-structures; and conditionally providing or not providing the content or one or more portions of the content, or access information of the content or one or more portions of the content, to the content searching or consuming application, by the search engine, based at least in part on the generated one or more scores; wherein the generating of a score for a structure further includes at each level, linearly iterating over one or more portions of the content at the level to capture potential of a portion to influence other portions of the level, and influence received by a portion from the other portions of the level. 22. The method of claim 13 , wherein the search expression comprises sub-expressions E 1 , . . . , E m , and wherein for portions of the content in a substructure at a level corresponds to content items at the level (N 1 , . . . , N k ), iterating over one or more portions of the content at the level to capture influences received by a portion from the other portions of the level comprises iterating over N 1 , . . . , N k , where for each sibling content item N i and for each search expression E j , content-tree-synthesized input to a pre-normalized relevance value for N i for E j is X j /(1+d i,j ) x , where X j is the influence capacity of a virtual content item corresponding to E j , where d i,j is the distance, according to the geometry, between N i and the virtual content item corresponding to E j , and where x is a distance attenuation exponent.