Theorem nftru 1480

Description: The true constant has no free variables. (This can also be proven in one step with nfv 1542, but this proof does not use ax-17 1540.) (Contributed by Mario Carneiro, 6-Oct-2016.)

Assertion

Ref	Expression
nftru	|- F/ x T.

Proof of Theorem nftru

Step	Hyp	Ref	Expression
1		tru 1368	. 2 |- T.
2	1	nfth 1478	1 |- F/ x T.

Syntax hints:   T. wtru 1365   F/wnf 1474

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-gen 1463

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1475

This theorem is referenced by:  nfmo  2065  dvelimc  2361  nfralw  2534  nfralxy  2535  nfrexw  2536  nfralya  2537  nfrexya  2538  nfreuxy  2672  nfsbc  3010  nfsbcw  3119  nfcsbw  3121  nfcsb  3122  nfiotaw  5223  nfriota  5887  nfixpxy  6776