Yes, var = var + 1 turns into an incf.

Here's a small program ...
Code:
B   VAR BYTE
W   VAR WORD

B = 0
W = 0

B = B + 1
W = W + 1
After compiling, a quick look in the .LST file reveals all.
Code:
                      00107 ; C:\PIC\ART\ASMVSPBP.PBP       00014   B = 0
                      00108         MOVE?CB 000h, _B
  00000000                M PREV_BANK = 0
0001   01BA               M         clrf    _B
                      00109 
                      00110 ; C:\PIC\ART\ASMVSPBP.PBP       00015   W = 0
                      00111         MOVE?CW 000h, _W
  00000000                M PREV_BANK = 0
0002   01B8               M         clrf    _W
  00000000                M PREV_BANK = 0
0003   01B9               M         clrf    (_W) + 1
                      00112 
                      00113 ; C:\PIC\ART\ASMVSPBP.PBP       00017   B = B + 1
                      00114         ADD?BCB _B, 001h, _B
  00000000                M PREV_BANK = 0
0004   0ABA               M         incf    _B,   F
                      00115 
                      00116 ; C:\PIC\ART\ASMVSPBP.PBP       00018   W = W + 1
                      00117         ADD?WCW _W, 001h, _W
  00000000                M PREV_BANK = 0
0005   0AB8               M         incf    _W,   F
0006   1903               M         btfsc   STATUS, Z
0007   0AB9               M         incf    (_W)   + 1, F