In addition to the ADD/ADC and SUB/SBC instructions, the 68HC05 has dedicated increment and decrement instructions to add one to or subtract one from a memory location, the accumulator, or the index register.
The AND, ORA, and EOR instructions, respectively, take the logical AND, inclusive OR, and exclusive OR of the accumulator and an operand and store the result in the accumulator.
COM, COMA, and COMX take the one's complement of a memory location, the accumulator, or the index register. The one's complement of a number is simply the binary inversion of its bits.