This is a variant of clueless special where grid5=gridX, therefore there is no need to display gridX. Grid5 can be used to show the overlapped regions & therfore can be used as an aid in solving.
This 1st puzzle is completely solvable using hidden singles
Code:
471......3....2.....85.7416.95...1....2.....8......57.51.....398...7........4..8.
..7.14...6.4..891...2.....4......1....5.....8.19.....5.......4.46.5...7....8.9...
.....6..2.6..12.3.....9....65.......7.1.....4........35...8...747....12..9..6...8
.8...41....27.5.34....9......5...76.13.........8.........8...1.8.1.57346.......7.
.................................................................................
..3....5987.49...15.63.2.........9...29...61..5......4....3....435....9...76..84.
.7.3...9....982.6..1.....8...8.....6.37........4....1.4........59..46.........643
......23...5.79...8.....96..73....2.........9.........1.9...3...2..9...63.751.8..
.158.47.......9....23.......96......4.......9.87...2...54...8.7......3.1..26.35..
Unhide the following for a walkthrough
tarek