intra-submap (where node ‘j’ was inserted into // submap ‘i’)
node在submap里面的时候,node和submap之间的关系表示为intra
intra --在内,内部
inter-submap constraints (where node ‘j’ was not inserted // into submap ‘i’).
node不在submap里面的时候,node和submap之间的关系表示为inter
inter --表示“在一起,交互”之义