(tense
 . (seq
    (seq
     (one-or-more time-tense)
     (one-or-more space-tense))
    (optional (comment "Motion in the indicated direction" (seq "mo'i" space-direction)))
    (comment "{di'i} = regularly\n{na'o} = typically\n{ru'i} = continuously\n{ta'e} = habitually\n<N> {roi}[{nai}] = happens [not] N times\n<N> {re'u} = for the Nth time"
	     (optional-choice
	      (seq "di'i|na'o|ru'i|ta'e" (optional "nai"))
	      (seq number "roi")
	      (seq number "roinai")
	      (seq number "re'u")))
    (optional (comment
	       "{pu'o} = will start in future\n{co'a} = is starting\n{xa'o} = started early\n{ca'o} = is happening\n{de'a} = about to pause\n{di'a} = has just resumed\n{za'o} = should have stopped\n{co'u} = is stopping {mo'u} = is finished\n{ba'o} = has stopped\n{co'i} = whole event as a single point in time"
	       "pu'o|co'a|xa'o|ca'o|de'a|di'a|za'o|co'u|mo'u|ba'o|co'i"))
    (optional (comment "Spatial repetition"
		       (seq "fe'e"
			    (choice
			     (seq "di'i|na'o|ru'i|ta'e" (optional "nai"))
			     (seq number "roi")
			     (seq number "roinai")
			     (seq number "re'u")))))))

(space-tense
 . (seq
    (optional space-direction)
    (optional (comment "{vi} = near\n{va} = medium\n{vu} = far" "vi|va|vu"))
    (optional (comment
	       "The area of space covered"
	       (seq
		(comment
		 "{ve'i} = small\n{ve'a} = medium\n{ve'u} = large\n{ve'e} = everywhere"
		 "ve'i|ve'a|ve'u|ve'e")
		(optional space-direction)
		(optional (comment
			   "{vi'i} = along a line\n{vi'a} = in an area\n{vi'u} = through a volume\n{vi'e} = through space and time"
			   "vi'i|vi'a|vi'u|vi'e")))))))

(space-direction
 . (comment
    "{be'a} (north) {du'a} (east) {ne'u} (south) {vu'a} (west)
{ca'u} (forward) {ti'a} (backward) {zu'a} (left) {ri'u} (right) {ga'u} (above) {ni'a} (below) {ru'u} (surrounding/orbiting)
{bu'u} (at same place as) {ne'a} (next to) {ne'i} (within) {pa'o} (transfixing/passing through) {re'i} (adjacent to) {te'e} (bordering)
{fa'a} (towards) {to'o} (away from) {ze'o} (outward from speaker)  {zo'i} (inward to speaker) {zo'a} (tangential to / passing)"
    "be'a|du'a|ne'u|vu'a|ca'u|ti'a|zu'a|ri'u|ga'u|ni'a|ru'u|bu'u|ne'a|ne'i|pa'o|re'i|te'e|fa'a|to'o|ze'o|zo'i|zo'a"))

(time-tense
 . (seq
    (comment "{pu} = past\n{ca} = present\n{ba} = future" (optional "pu|ca|ba"))
    (comment "{zi} = near\n{za} = medium\n{zu} = far" (optional "zi|za|zu"))
    (optional (seq
	       (comment "{ze'i} = briefly\n{ze'a} = medium\n{ze'u} = prolonged\n{ze'e} = forever" "ze'i|ze'a|ze'u|ze'e")
	       (comment "{pu} = interval extends to past\n{ca} = interval surrounds point\n{ba} = interval extends to future"(optional "pu|ca|ba"))))))

