Add case for splitting headings

modules/fontane/teisimpleprint/tidysimple.xqm

@@ -365,6 +365,7 @@ declare function tidySimple:split-headings($nodes as node()*) as node()* {
                             $split-bottom
                         })
                     }
+                    
             else
                 element {QName("http://www.tei-c.org/ns/1.0", $node/name())} {
                     $node/@*,
@@ -374,6 +375,21 @@ declare function tidySimple:split-headings($nodes as node()*) as node()* {
         default return
             element {QName("http://www.tei-c.org/ns/1.0", $node/name())} {
                 $node/@*,
+                if($node/tei:add[@type = "edited_text" and @subtype = "interlinear"]) then
+                    let $add := $node/tei:add[@type = "edited_text" and @subtype = "interlinear"]
+                    return
+                        (element {QName("http://www.tei-c.org/ns/1.0", "seg")} {
+                            attribute type {"upper-part"},
+                            $add/node()
+                        },
+                        element {QName("http://www.tei-c.org/ns/1.0", "lb")} {
+                            attribute type {"edited_text"}
+                        },
+                        element {QName("http://www.tei-c.org/ns/1.0", "seg")} {
+                            attribute type {"lower-part"},
+                            $add/following-sibling::node()
+                        })
+                else
                     tidySimple:split-headings($node/node())
             }
 };
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