Theorem nftru 1476

Description: The true constant has no free variables. (This can also be proven in one step with nfv 1538, but this proof does not use ax-17 1536.) (Contributed by Mario Carneiro, 6-Oct-2016.)

Assertion

Ref	Expression
nftru	|- F/ x T.

Proof of Theorem nftru

Step	Hyp	Ref	Expression
1		tru 1367	. 2 |- T.
2	1	nfth 1474	1 |- F/ x T.

Syntax hints:   T. wtru 1364   F/wnf 1470

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 1459

This theorem depends on definitions:  df-bi 117  df-tru 1366  df-nf 1471

This theorem is referenced by:  nfmo  2056  dvelimc  2351  nfralw  2524  nfralxy  2525  nfrexxy  2526  nfralya  2527  nfrexya  2528  nfreuxy  2662  nfsbc  2995  nfcsbw  3105  nfcsb  3106  nfiotaw  5194  nfriota  5853  nfixpxy  6731