This puzzle is a diagramless crossword, where all clues are presented in a single, undifferentiated list, with only a set of 10 context-free grammars mapping clues to grid entries. Solvers need to solve the clues and determine the mappings between clues and grid entries via the grammars.
Additionally, the grammars provide information to help fill out the grid. E.g. grammar S6 can be used to determine that the seven clues matching it are all 4 letter words starting with B, M, O, R, or T, helping to fill the grid even if the matching crossword clues have not been solved yet.
Once the grid has been solved, the final extraction is performed by finding locations where the clues matching a given grammar intersect themselves (one per grammar) and reading them out in S1–S10 order (which is also grid order). This gives the answer CHECKPOINT
.
Filled grid with extracted letters highlighted:
S | T | R | E | G | A | |||||||||
T | M | C | T | H | E | M | E | S | A | R | M | |||
O | A | R | E | E | V | E | E | S | L | E | A | |||
S | L | A | T | P | O | E | L | O | B | S | ||||
H | I | G | H | V | O | C | A | B | P | E | S | T | ||
R | E | N | L | O | A | M | S | |||||||
E | D | S | E | L | S | O | C | O | T | I | P | |||
L | I | K | E | C | R | O | S | S | E | S | L | I | K | E |
M | A | Y | R | E | P | O | C | O | M | E | T | |||
M | O | D | A | L | S | O | Y | |||||||
I | O | T | A | L | U | F | T | W | A | F | F | E | ||
K | N | E | X | T | O | R | L | O | O | M | ||||
E | A | R | R | E | H | I | R | E | N | A | M | |||
A | N | N | S | A | B | O | T | S | E | L | Y | |||
S | T | O | N | E | S |
Crossword clue and grammar pairings:
ASS
ANN
TIM
TMC
EME
CRAG
GEE
LPS
VELCRO
MAX
MAY
THEMES
THREE
THEOC
FOAL
PEST
HBO
KNEX
ALOE
PET
EMMY
POE
DIA
OAR
TOR
SOCO
ACE
ARM
TIP
REHIRE
LUFTWAFFE
SOY
SKY
STONES
LIKECROSSESLIKE
EEVEES
TOSH
MALI
BOOS
ONAN
OPAL
MAST
TERN
REPO
REBS
MODAL
EAT
LEA
COMET
EAR
LOBS
LOYAL
STEPON
IOTA
IKE
LOOM
ELY
ELM
LOAMS
IKEA
RED
FONE
REVEALSSOLUTION
REN
STRESS
NAM
RSS
HIGHVOCAB
STREGA
SABOTS
EDSEL
FORTE
MOSCOW
SLAT