AND as an inverted-input NOR — AND gate

exam standardthe alternative IEEE symbol

Answer

verified equivalent (both sides → A · B)

Why this example is worth doing

The De Morgan equivalent symbol for AND: a NOR body with bubbles on both inputs. It is the same physical function, drawn differently so that bubbles cancel against whatever drives it. Seeing the AND page carry an OR-shaped symbol is jarring the first time, which is the point — schematic reading requires recognising a gate by its bubble pattern rather than by its outline, and this page is where that habit starts.

Try your own input in the AND gate. Truth table, symbol and algebraic form for A·B, with a live two-input toggle.

How the answer is reached

The law

A · B(A′ + B′)′Both sides have the same truth table over the union of their variables.

Truth table

Truth table — columns #, A, B, F
#ABF
0000
1010
2100
3111

Compare with

Open the AND gate

This input is entered in the tool itself — it is too rich for a link to carry.

Note:

Notation this page assumes

  • Symbols: · is AND, + is OR, ⊕ is XOR, a prime or an overline is NOT. The field also takes ∧ ∨ ¬ ~ ! & | and the words.
  • Operator precedence, tightest first: NOT, then AND (including juxtaposition), then XOR/XNOR, then NAND/NOR, then OR, then IMPLIES, then IFF.
  • Gate symbols follow whichever standard the header toggle is set to: ANSI/IEEE Std 91-1984 distinctive shapes, or IEC 60617-12 rectangles.

Sources

  • ANSI/IEEE Std 91-1984, Graphic Symbols for Logic Functions
  • IEC 60617-12, Graphical Symbols for Diagrams — Binary Logic Elements