validate_check_p_m
Positive input (Valid):
L+
L-
L-1
L+1
L-2
L+2
L-3
L+3
L-9
L+9
L-10
L+10
L+90
L+100
L+900

Positive (_NA):
L0
L1
L100
LL
Lasd
L9
L90
L900

Negative (Invalid):
L+0
L-0
L--
L++
L+L
L-L
L+asd
L-asd
L-0-
L+0+
L+0-
L-0+
L-0

Overall results: Tested OK. Seems like its working like it should now. 

validate_check_imm
Positive input (Valid):
L
L1
L9
L10
L90 
L900 
L100 

Negative (Invalid):
LL 
L+ 
L+1 
L0 
L+0 
L00 
L0L 

Overall results: Tested OK. Seems like its working like it should.

validate_plus_continue
Positive input (Valid):
L+1
L+10
L+9
L+90
L+5
L+50
L+11
L+99
L+345345
L+12313213213213

Negative (Invalid):
L+1L
L+11L
L+9L
L+5L
L+90L
L+500+
L+23+23
L+13++
L-10
L+1+

Overall results: Tested OK. Seems fine.

validate_imm_numbers
Positive input (Valid):
L1
L2
L9
L10
L10000
L999
L1112
L3987453

Negative (Invalid):
L1-
L9+
L1L
L9a
L1F
L9e
L100000000L
L942sA
L223+213123
L2+1

Overall results: Tested OK. Seems fine.

validate_L
Positive (valid):
L
L+ 
L- 
L1 
L10 
L9 
L90 
L5 
L50 
L500 
L900 
L100
L9993221
L100000000000
L9234572
L112323
L100334
L+1 
L-1 
L+10
L+9
L+90 
L+1000000000
L+9992
L+1020023023
L-2323232323 

Negative (invalid):
L++
L--
L+0
L-0
L0
L00 
LL 
LN 
Lsada
L+a
L+abcdefg 
L-a 
L+0111a
L01203103
L11212
L+12n
L10+10
L10-10
L-1-1+1-1
L+1+1+1
L10+10+10
L+10+1000
L10+10
l+10l
L10?
L+10?
L?10

Overall resuts: Tested OK. I don't think ive missed any checks for anything but hey you can never be sure. This is acceptable for now.