@prefix isq: <https://w3id.org/standards/isq/ontologies/core/> .
@prefix smart: <https://example.org/smart-sdu/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<isq:t2-18.18>
  a isq:Entry ;
  rdf:type isq:MathConcept ;
  rdf:type smart:TermEntry ;
  dcterms:identifier "2-18.18" ;
  skosxl:prefLabel "d'Alembertian"@en ;
  skosxl:altLabel "square"@en ;
  skos:definition "d'Alembertian"@en ;
  smart:hasBindingnessType "bindingness-type:normative" ;
  dcterms:isPartOf <isq:part-2-18> ;
  skos:note "stem:[square = (del^2)/(del x^2) + (del^2)/(del y^2) + (del^2)/(del z^2) - 1/(c^2) (del^2)/(del t^2)]\n\nwhere the independent variable stem:[t] is time (<<iso80000-3>>) and stem:[c] is the speed (<<iso80000-3>>) of light\n"@en ;
  iso:urn <urn:iso:std:iso:80000:-2:ed-2:en:item:2-18.18> .